WO2024134797A1 - Information processing device, simulation method, and simulation program - Google Patents

Abstract

In order to improve the convenience of simulation based on the results of causal analysis, an information processing device (1) comprises: an element extraction unit (11) that, in a simulation that changes the value of an objective variable to a target value, extracts, for each mode of the simulation, an element corresponding to the mode from among the plurality of elements causally connected to the objective variable; and a display control unit (12) that displays the extracted elements for each mode as target elements of which values are to be changed in order to change the objective variable to the target value.

Description

Information processing device, simulation method, and simulation program

The present invention relates to an information processing device that performs processing related to causal analysis.

A method known as causal analysis is known for discovering causal relationships between multiple elements based on data related to each of the elements. For example, the following Patent Document 1 describes constructing a directed acyclic graph that represents the relationships between multiple variables and a target outcome. The same document also describes using the constructed directed acyclic graph to analyze whether there is sufficient causal evidence to identify a causal relationship between a variable of interest and the target outcome.

JP 2019-194849 A

In the conventional technologies described above, there is room for improvement in terms of the convenience of performing simulations based on the results of causal analysis. In other words, if the causal relationships between elements are clarified by causal analysis, it is possible to simulate what values other elements need to have in order to set a certain element's value to a target value. However, when there are a large number of elements that are causally connected to the element to be set as the target value, it is cumbersome to decide on a policy for selecting elements whose values will be changed and to extract elements in accordance with that policy. Furthermore, such work is difficult for those who are unfamiliar with causal analysis.

One aspect of the present invention aims to realize an information processing device or the like that can improve the convenience of simulations based on the results of causal analysis.

An information processing device according to one aspect of the present invention includes an element extraction means for extracting one or more elements corresponding to each mode of the simulation from among a plurality of elements causally linked to the objective variable in a simulation in which the value of one of the elements, an objective variable, is changed to a target value based on the results of a causal analysis of the plurality of elements, and a display control means for displaying the extracted elements for each mode as target elements whose values should be changed in order to change the objective variable to the target value.

A simulation method according to one aspect of the present invention includes, in a simulation in which at least one processor changes the value of a target variable, which is one of a plurality of elements, to a target value based on the results of a causal analysis of the plurality of elements, extracting one or more elements corresponding to each mode of the simulation from among the plurality of elements that are causally linked to the target variable, and displaying the extracted elements for each mode as target elements whose values should be changed in order to change the target variable to the target value.

A simulation program according to one aspect of the present invention causes a computer to function as an element extraction means for extracting one or more elements corresponding to each mode of a simulation from among a plurality of elements causally linked to a target variable in a simulation in which the value of the target variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of the plurality of elements, and as a display control means for displaying the extracted elements for each mode as target elements whose values should be changed in order to change the target variable to the target value.

According to one aspect of the present invention, it is possible to improve the convenience of simulations based on the results of causal analysis.

1 is a block diagram showing a configuration of an information processing device according to a first exemplary embodiment of the present invention; FIG. 2 is a flow chart showing the flow of a simulation method according to the first exemplary embodiment of the present invention. FIG. 11 is a block diagram showing a configuration of an information processing device according to an exemplary embodiment 2 of the present invention. FIG. 13 is a diagram showing an example of a display screen displayed during a simulation. FIG. 13 is a diagram showing an example of an image for receiving designation of a target element. FIG. 13 is a diagram showing an example of a display screen when a target element is added; FIG. 11 is a flow chart showing the flow of a simulation method according to an exemplary embodiment 2 of the present invention. FIG. 1 is a diagram showing an example of a computer that executes instructions of a program, which is software that realizes the functions of each device according to each exemplary embodiment of the present invention.

[Example embodiment 1]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. This exemplary embodiment is a basic form of the exemplary embodiments described below.

(Configuration of information processing device)
The configuration of an information processing device 1 according to this exemplary embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the configuration of the information processing device 1. As shown in the figure, the information processing device 1 includes an element extraction unit 11 and a display control unit 12.

The element extraction unit 11 extracts one or more elements corresponding to each simulation mode from among the multiple elements that are causally linked to the objective variable in a simulation in which the value of the objective variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of multiple elements.

The display control unit 12 displays the elements extracted by the element extraction unit 11 for each mode as target elements whose values should be changed in order to change the objective variable to the target value.

As described above, the information processing device 1 according to this exemplary embodiment is configured to include an element extraction unit 11 that extracts one or more elements corresponding to each simulation mode from among the multiple elements that are causally linked to the objective variable in a simulation in which the value of one of the elements, an objective variable, is changed to a target value based on the results of a causal analysis of the multiple elements, and a display control unit 12 that displays, for each mode, the elements extracted by the element extraction unit 11 as target elements whose values should be changed to change the objective variable to the target value. Therefore, the information processing device 1 according to this exemplary embodiment has the effect of improving the convenience of the simulation.

(Simulation program)
The above-mentioned functions of the information processing device 1 can also be realized by a program. The simulation program according to the present exemplary embodiment is configured to make a computer function as an element extracting means for extracting one or more elements corresponding to each mode of a simulation from among a plurality of elements causally connected to a target variable in a simulation in which the value of a target variable, which is one of the elements, is changed to a target value based on the result of a causal analysis of the plurality of elements, and a display control means for displaying the elements extracted by the element extracting means for each mode as target elements whose values should be changed to change the target variable to the target value. Therefore, the simulation program according to the present exemplary embodiment has an effect of improving the convenience of the simulation.

(Flow of simulation method)
The flow of the simulation method according to the present exemplary embodiment will be described with reference to Fig. 2. Fig. 2 is a flow diagram showing the flow of the simulation method. Note that the execution subject of each step in this simulation method may be a processor provided in the information processing device 1, a processor provided in another device, or a processor provided in a different device.

In S11, at least one processor performs a simulation in which the value of a target variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of the multiple elements, and extracts one or more elements corresponding to each simulation mode from among the multiple elements that are causally linked to the target variable.

In S12, at least one processor displays the elements extracted in S11 for each mode as target elements whose values should be changed to change the objective variable to a target value.

As described above, the simulation method according to this exemplary embodiment employs a configuration including the steps of: in a simulation in which at least one processor changes the value of a response variable, which is one of a plurality of elements, to a target value based on the results of a causal analysis of the plurality of elements; extracting, for each simulation mode, one or more elements corresponding to the mode from among the plurality of elements that are causally linked to the response variable; and displaying, for each mode, the extracted elements as target elements whose values should be changed in order to change the response variable to the target value. Therefore, the simulation method according to this exemplary embodiment has the effect of improving the convenience of the simulation.

Exemplary embodiment 2
(Configuration of information processing device)
The configuration of the information processing device 2 according to this exemplary embodiment will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the configuration of the information processing device 2. As shown in the figure, the information processing device 2 includes a control unit 20 that controls each unit of the information processing device 2, and a storage unit 21 that stores various data used by the information processing device 2. The information processing device 2 also includes a communication unit 22 that allows the information processing device 2 to communicate with other devices, an input unit 23 that accepts input of various data to the information processing device 2, and a display unit 24 that allows the information processing device 2 to display and output various data. Note that each of the components from the storage unit 21 to the display unit 24 may be built into the information processing device 2, or may be an external device attached to the information processing device 2.

The control unit 20 also includes a reception unit 201, a causal analysis unit 202, an element extraction unit 203, a change index calculation unit 204, a path coefficient calculation unit 205, a condition satisfaction determination unit 206, an element determination unit 207, a display control unit 208, and a simulation execution unit 209.

The reception unit 201 receives various specifications from the user regarding the simulation. For example, the reception unit 201 receives the specification of an element to be used as a response variable in the simulation from among multiple elements causally analyzed by the causal analysis unit 202, and the specification of a target value for the response variable. The term "element" will be explained in the next paragraph.

The causal analysis unit 202 performs causal analysis on multiple given elements, and identifies the causal structure and causal relationships between those elements. There are no particular limitations on the elements that are the subject of the causal analysis. For example, the elements that are the subject of the causal analysis may be each question in a questionnaire and the answers to those questions, or the elements that are the subject of the causal analysis may be the actions and their results shown in the behavioral history information of a subject or group of subjects. In addition, the data format of each element may or may not be standardized. The causal analysis unit 202 may perform the causal analysis by applying known causal inference or causal search methods that correspond to the target elements, etc.

Below, we will explain an example where each element is a variable related to a certain event. For example, when performing causal analysis on various events related to product sales, a variable related to the event of a product being purchased (for example, a numerical value indicating the number of products purchased or the sales price) can be an element. In addition, a variable indicating the price of a product, which is related to the above event, can also be an element.

By performing causal analysis, it becomes possible to predict how one of the variables related to such causally-linked elements will change when the other variable is changed. For example, in the above example, it is possible to predict the number of units sold when the unit price of the product is reduced by 10%, or conversely, to predict how much the unit price of the product needs to be reduced in order to bring the number of units sold above a threshold. In other words, it is possible to identify the relationship between a certain variable as an explanatory variable and another variable that is causally-linked to that variable as a target variable.

Note that the information processing device 2 does not necessarily need to include the causal analysis unit 202. If the information processing device 2 does not include the causal analysis unit 202, it is sufficient for the information processing device 2 to acquire the results of the causal analysis performed in another device via the communication unit 22 or the input unit 23.

The element extraction unit 203 extracts one or more elements corresponding to each simulation mode from among multiple elements that are causally linked to the target variable in a simulation performed by the simulation execution unit 209. The elements extracted by the element extraction unit 203 become explanatory variables in the simulation.

The simulation mode can be said to be the style of the simulation or the simulation policy. The simulation mode may be determined in advance, or the user may be able to set some or all of the modes. For example, a mode may be set in which the number of explanatory variables used is limited to a certain number or less, or a mode in which at least one explanatory variable is extracted from each of multiple paths. In this way, each mode may have a rule set in advance for determining the elements to be used as explanatory variables in that mode. The mode can also be said to specify the range of explanatory variables. Note that a "path" is a series of elements that has the objective variable as the end element and includes one or more explanatory variable elements that are directly or indirectly causally connected to that element.

Furthermore, each element that has undergone causal analysis can be represented in a causal graph. In a causal graph, each element is represented as a "node," and the causal relationships between each element are represented as "edges" connecting the nodes. Furthermore, nodes are classified into RCVs (Root Cause Variables), which are the start points of paths, targets, which are the end points of paths, and variables located between the RCVs and targets. Thus, a "path" can also be expressed as a route consisting of one or more edges connecting an RCV and a target, or as a matrix of nodes from an RCV to a target that are connected by edges. Furthermore, a "path" can be classified into direct paths, which directly connect an RCV and a target, and indirect paths, which involve one or more variables between the RCV and the target.

The target, which is the end point of the path, is sometimes called the objective variable, response variable, reaction variable, outcome variable, dependent variable, or non-explanatory variable. The RCV, which is the start point of the path, and the variables located between the RCV and the target are sometimes called explanatory variables, predictor variables, or independent variables.

The change index calculation unit 204 calculates an index value that indicates the degree of change in the objective variable (which can also be called the target variable) when the value of each element that is causally linked to the objective variable is changed, that is, when the value of the element, i.e., the value of the explanatory variable, is changed.

The index value indicating the degree of change may, for example, indicate the amount of change or the rate of change. For example, the change index calculation unit 204 may calculate the amount of change in the objective variable when the explanatory variable is increased by a predetermined amount (for example, 1) as the index value. This index value can be calculated by multiplying the amount of change in the explanatory variable by a path coefficient, which will be described later. Note that, when there are multiple paths, the index value can be calculated by the sum of the products of the amount of change in the explanatory variable and each path coefficient. Similarly, it is also possible to calculate the rate of change in the objective variable when the explanatory variable is increased by a predetermined amount or a predetermined rate.

The index value may also indicate a change in a statistical quantity. For example, the change index calculation unit 204 may calculate the index value indicating a change in a statistical quantity of the objective variable when the explanatory variable is increased by a predetermined amount (for example, 1). The statistical quantity may be, for example, a standard deviation. For example, the change index calculation unit 204 may calculate, as the index value, the ratio of the standard deviation of the objective variable after the explanatory variable is changed to the standard deviation of the objective variable before the explanatory variable is changed. Also, the user may be able to specify the statistical quantity to be targeted.

The path coefficient calculation unit 205 calculates the path coefficient of the path connecting each element causally connected to the objective variable and the element set as the objective variable. The path coefficient is a coefficient calculated using the weight of each edge connecting each element that has been causally analyzed. Specifically, for a direct path, the path coefficient calculation unit 205 calculates the weight of the edge that constitutes the path. For an indirect path, the path coefficient calculation unit 205 calculates the product of the weights of the multiple edges that constitute the path. Note that the product of the edge weights is merely one example of a path coefficient, and path coefficients may be calculated using other methods. It can be said that a path with a larger path coefficient value is more likely to be a useful path.

The condition satisfaction determination unit 206 determines whether or not each of the elements causally linked to the objective variable satisfies a predetermined condition. Any condition can be set, and the user may be allowed to set the conditions. For example, conditions may be set regarding the index value calculated by the change index calculation unit 204, the path coefficient calculated by the path coefficient calculation unit 205, and the like. As a specific example, the condition satisfaction determination unit 206 may determine that an element whose index value is equal to or less than a predetermined threshold satisfies the condition, and that an element whose index value is less than the threshold does not satisfy the condition.

When the objective variable does not reach the target value in a simulation, the element determination unit 207 determines an element that is causally linked to the objective variable to be used as a target element instead of or in addition to the target element applied in the simulation. Note that the target element is an element extracted by the element extraction unit 203.

The display control unit 208 displays, for each mode, the elements extracted by the element extraction unit 203 as target elements whose values should be changed in order to change the objective variable to the target value. The display format may be any format that allows the user to recognize the mode and the corresponding target element. A specific example of the display of the target elements will be explained later in the section "Example of a display screen during simulation."

The simulation execution unit 209 performs a simulation based on the results of the causal analysis performed by the causal analysis unit 202 on multiple elements. Specifically, the simulation execution unit 209 calculates the value of each target element to bring the objective variable to a target value. In other words, the simulation execution unit 209 predicts how to change the value of the target element to change the objective variable to the target value.

(Example of display screen during simulation)
Fig. 4 is a diagram showing an example of a display screen displayed during a simulation by the display control unit 208. The example of the display screen in Fig. 4 includes an area a1 for receiving input of simulation conditions, areas a2 and a3 for displaying the results of the simulation, and an area a4 for displaying a causal graph.

(Regarding region a1)
Area a1 displays an object a11 for receiving a designation of a response variable, an object a12 for receiving a designation of a target value, and an object a13 for receiving a designation of a candidate target element, which is an element to be subjected to the simulation, and an object a14 for receiving a designation of a condition for the simulation.

The user selects object a11 by performing an input operation via the input unit 23, and specifies the element to be used as the objective variable. For example, when object a11 is selected, the display control unit 208 may display a list of elements that have been subjected to causal analysis and can be used as the objective variable, and allow the user to specify an element to be used as the objective variable from the list of elements. When the user specifies an element, a character string indicating the specified element ("Livability" in the example of FIG. 4) is displayed on object a11.

Object a12 is an object in which a slider that can be moved on a slider bar is placed on the slider bar. The slider bar indicates the range in which the value of the objective variable can be changed, and the position of the slider indicates the target value. The user specifies the target value by moving the slider to the desired position through an input operation via the input unit 23. In the example of FIG. 4, the target value is specified as "4.0".

The user also selects object a13 by performing an input operation via input unit 23, and specifies a candidate for the target element. When the user specifies a candidate, a character string indicating the specified candidate (such as "childcare facility" or "park" in the example of FIG. 4) is displayed on object a13. At this time, display control unit 208 may display a list of elements that can be used as candidates for the target element, i.e., elements that are causally linked to the objective variable, and allow the user to specify an element from among the conditions displayed in the list. This will be explained later in the section "Regarding acceptance of candidate specification."

Object a14 includes object a141 for accepting the specification of attributes of the data used in the causal analysis, object a142 for accepting the specification of a symbol, and object a143 for accepting the specification of a numerical value. By performing input operations via input unit 23, the user selects object a141 to specify an attribute, selects object a142 to specify a symbol, and selects object a143 to specify a numerical value. The content specified by the user is displayed on objects a141 to a143. Specifically, "Age", "≧", and "30" are displayed. In other words, the condition specified is that the simulation will be performed based on data for people 30 years of age or older.

Here, if the conditions of the simulation are changed, the causal analysis unit 202 may perform causal analysis again under the changed conditions. For example, if the age is specified as 30 years or older as in the example of FIG. 4, the causal analysis unit 202 may perform causal analysis again using data for people 30 years or older (for example, responses from people aged 30 years or older who responded to a questionnaire). The causal analysis unit 202 may also update the values of variables to those according to the specified conditions without updating the causal relationships.

(Regarding the acceptance of candidate designations)
When the object a13 is selected, the display control unit 208 may display an image as shown in Fig. 5 to allow the user to specify a candidate target element. Fig. 5 is a diagram showing an example of an image for receiving the specification of a candidate target element.

Image b1 in FIG. 5 displays a list of character strings such as "childcare facility" that indicate each element that can be a target element. Elements that can be a target element are elements that are causally linked to the objective variable and can change depending on the specified objective variable.

In addition, image b1 displays a check box corresponding to each character string. The user can specify the corresponding element as a candidate for the target element by checking the check box through an input operation via the input unit 23. In the example of FIG. 5, the check box is selected with the cursor Cu to specify the candidate for the target element. The specified elements with checked check boxes are "childcare facility" and "park."

In the example of FIG. 5, a speech bubble b2 is displayed for "childcare facility", which is the element over which the cursor Cu is placed. Speech bubble b2 shows information that will be used to decide whether or not to select "childcare facility" as a candidate for the target element. Specifically, speech bubble b2 shows that the path coefficient of the path connecting "childcare facility" and the objective variable ("livability" in the example of FIG. 4) is "0.4", the cost of changing the value of the element by a specified amount, etc.

The above "cost" includes at least one of monetary cost, time cost, and human cost. The cost required to change the value of each element by a unit amount can be specified in advance. For example, if the numerical values such as the amount of money, time, or number of people required to increase the value of each element by one point are specified in advance and stored in the storage unit 21, the display control unit 208 can display the cost values.

The path coefficients may be calculated by the path coefficient calculation unit 205. Note that the information used to determine whether or not to select a target element as a candidate is not limited to these examples. For example, the index value calculated by the change index calculation unit 204, the determination result of the condition satisfaction determination unit 206, etc. may be displayed. Furthermore, the method of displaying this information is arbitrary and is not limited to the example shown in the figure.

The element extraction unit 203 extracts target elements for each simulation mode from among the candidate target elements specified as described above. Note that it is not essential to specify candidate target elements. If candidate target elements are not specified, the element extraction unit 203 extracts target elements from among the elements that are causally linked to the objective variable.

As described above, the display control unit 208 may display, for each of a plurality of elements causally linked to the objective variable, at least one of an index value indicating the degree of change in the objective variable when the value of the element is changed, a path coefficient of a path connecting the element and the objective variable, and a cost for changing the value of the element by a predetermined amount. Then, the reception unit 201 may receive a selection of a plurality of elements causally linked to the objective variable, and the element extraction unit 203 may extract one or more elements including the element selected by the reception unit 201 as target elements. This allows the user to select target elements taking into consideration the above-mentioned index values and costs.

(Regarding region a2)
In the example of FIG. 4, target elements are extracted for each of the "balance mode" and "single conversion mode", and the results of the simulation for each of these modes are displayed in areas a2 and a3. The "balance mode" is a mode in which a simulation is performed in which multiple target elements are changed. In the "balance mode", the values of each target element may be changed at a constant ratio or amount, or may be changed by individual values or ratios. The "single conversion mode" is a mode in which a simulation is performed using one target element (e.g., the target element with the highest intervention effect). The element extraction unit 203 extracts target elements corresponding to each mode according to the rules for each mode.

Note that the above-mentioned "balanced mode" and "single conversion mode" are merely examples of "modes" in this exemplary embodiment, and the "modes" in this exemplary embodiment are not limited to these examples. For example, a mode in which a simulation is performed using the top n target elements (n is an integer) with the highest intervention effect may be applied.

Area a2 shown in Figure 4 displays the character string "Balance Mode" indicating the simulation mode, the set target value, and information indicating the change in the objective variable. Specifically, it shows that the simulation is to increase the value of the objective variable "livability" from 3.0 to 4.0 (a 33% increase). It is also possible to perform a simulation that decreases the values of the objective variable and explanatory variables.

In addition, area a2 displays character strings such as "ease of childcare" indicating each element extracted as a target element in the balance mode, and information indicating how to change the target elements to change the objective variable to the target value. Specifically, it shows that the objective variable can be changed to the target value by changing the current value of the target element "ease of childcare" from "3.1" to "4.5" (a 45% increase), changing the value of "childcare facilities" from "2.5" to "4.3" (a 72% increase), and changing the value of "parks" from "2.8" to "4.2" (a 50% increase).

In this way, the display control unit 208 may not only display the target elements for each mode, but also display information indicating how to change the values of the target elements to change the objective variable to the target value. This provides the effect of allowing the user to recognize how to change the values of the target elements to bring the objective variable to the target value, in addition to the effect provided by the information processing device 1 according to the first exemplary embodiment. Note that it is not essential to display the information indicating how to change the values of the target elements, and it is sufficient for the display control unit 208 to display at least the target elements for each mode.

(Regarding region a3)
In the area a3, a character string "single conversion mode" indicating the simulation mode and a set target value (4.0) are displayed. In this example, the value of "livability" has not reached the target value, and a numerical value of "-0.6" indicating that the result is 0.6 below the target value is displayed in association with the target value. In addition, in the area a3, information indicating a change in the objective variable is displayed. Specifically, it is shown that the value of the objective variable "livability" has increased from 3.0 to 3.4, and the increase rate is 13%.

In addition, area a3 displays the character string "Ease of childcare", which indicates the element extracted as the target element in the single conversion mode, and information indicating how to change the target element to change the objective variable as described above (increasing it from 3.0 to 3.4). Specifically, it shows that the objective variable can be increased to 3.4 by changing the current value of the target element "Ease of childcare", "3.1", to its maximum value, "5.0" (a 61% increase).

In this way, if the objective variable does not reach the target value by changing the value of the target element extracted by the element extraction unit 203, the simulation execution unit 209 may calculate a value that brings the objective variable closest to the target value. Note that, as explained below in "Processing when the target value is not reached," if the target value is not reached, a target element may be added and the simulation may be performed again.

(Regarding region a4)
Next, the area a4 for displaying the causal graph will be described. A causal graph is a graph in which multiple elements that have been causally analyzed are represented by nodes, and the causal relationships between the elements are indicated by directed edges (one-way arrows), and is also called a directed acyclic graph. The causal graph displayed in the area a4 consists of seven nodes N1 to N7. Note that instead of a directed acyclic graph, a CPDAG (Completed Partially Directed Acyclic Graph) or an undirected graph may be displayed.

Displaying a causal graph allows the user to easily recognize the relationships between each element. For example, in the example of Figure 4, the directed edge extending from node N3 (childcare facilities) connects to node N2 (ease of raising children), and the directed edge extending from node N2 connects to node N1 (ease of living). This allows the user to recognize at a glance that "childcare facilities" affect "ease of raising children," and "ease of raising children" affects "ease of living."

In addition, in the causal graph shown in Figure 4, numerical values are displayed in association with each node. These numerical values indicate the values of the variables (explanatory variables or objective variables) of each node. For example, the numerical value "4.1" is associated with node N6 (waterside environment), which indicates that the value of the explanatory variable corresponding to node N6 is 4.1.

Furthermore, in this causal graph, nodes N2 to N4 are indicated by dashed circles, and node N1 is indicated by a thick circle. The dashed circle indicates that the element corresponding to that node is the target element extracted by element extraction unit 203, and the thick circle indicates that the variable corresponding to that node is set as the target variable of the simulation.

In addition, the elements extracted as target elements for the balance mode are indicated by dashed circles in this causal graph. To indicate this, the display control unit 208 displays the frame line surrounding the area a2 corresponding to the balance mode in bold. The user may be allowed to select which mode's target elements are to be displayed on the causal graph.

In this way, the display control unit 208 may display the nodes corresponding to the target elements extracted by the element extraction unit 203 on the causal graph so that they can be distinguished from other nodes. This allows the user to recognize the positioning of the target elements in the entire causal graph and the relationships between the target elements.

In addition, the results of the simulation are shown at nodes N1 to N4. Specifically, it shows that by increasing the value of "childcare facilities" from "2.5" to "4.3" and the value of "parks" from "2.8" to "4.2", and thereby increasing the value of "ease of raising children", which is downstream of these elements, from "3.1" to "4.5", it is possible to increase "livability" from the current level of "3.0" to the target value of "4.0".

In this way, the display control unit 208 may display on the causal graph information indicating how to change the value of the target element in order to change the objective variable to the target value. This allows the user to recognize how a change in the variable of a certain target element ripples out and affects the objective variable.

The display manner of the target elements is not limited to the illustrated example, and may be any manner that allows the user to recognize the mode and the corresponding target element. For example, the display control unit 208 may display the target elements by displaying a path from the element of the objective variable to the element extracted by the element extraction unit 203. For example, in the case of the "balanced mode" in FIG. 4, the display control unit 208 may display a path from node N3 to node N1 via node N2, and a path from node N4 to node N1 via node N2. The branch may be treated as one path, in which case a path consisting of node N1 to node N4 may be displayed.

(Processing when target value is not reached)
As described above, if the objective variable does not reach the target value by changing the value of the target element extracted by the element extraction unit 203, the target element may be added and the simulation may be performed again. This will be described with reference to Fig. 6. Fig. 6 is a diagram showing an example of a display screen when a target element is added. More specifically, Fig. 6 shows another example of the display in the area a3 in Fig. 4.

If the objective variable does not reach the target value by changing the value of the target element extracted by the element extraction unit 203, the display control unit 208 may display an object a31 for accepting addition or modification of the target element, as shown in FIG. 6. In the example of FIG. 6, the target value is not reached in the single conversion mode, and object a31 is displayed in area a3, which is the display area for the simulation results in that mode.

Furthermore, when a user performs an operation to select object a31, the display control unit 208 may display a list of selectable elements and allow the user to specify a target element to be added. For example, the display control unit 208 may display image c1 shown in FIG. 6. Image c1 displays a character string (specifically, "ease of childcare") indicating the target element applied in the simulation that did not reach the target value, as well as a list of character strings such as "waterside environment" indicating target elements that can be added. Target elements that can be added are elements that are causally linked to the objective variable and that were not applied in the previous simulation.

In addition, image c1 displays a check box corresponding to each character string. The user can specify the target element to be added by checking the check box through an input operation via input unit 23. The user can also uncheck the check box corresponding to a target element that was applied in the previous simulation so as not to apply that target element. In the example of FIG. 6, the target element applied in the previous simulation, "ease of raising children," remains as is, and "waterside environment" and "green space area" are specified as target elements to be added.

When the target element is specified in the above manner, the element extraction unit 203 extracts the specified target element, and the simulation execution unit 209 performs a simulation again using the extracted target element. This identifies how to change the value of the target element to change the objective variable to the target value.

FIG. 6 also shows an example in which the results of a re-simulation are displayed in area a3. In the re-simulation, "waterside environment" and "green area" have been added as target elements. In this way, when the objective variable does not reach the target value by changing the value of the displayed target element, the display control unit 208 may display other elements that are causally linked to the objective variable ("waterside environment" and "green area" in the example of FIG. 6) instead of or in addition to the target element. This provides the effect of the information processing device 1 according to the first exemplary embodiment, as well as the effect of allowing the user to consider measures to bring the objective variable to the target value, including elements that were not displayed as target elements.

Furthermore, for each target element, information is displayed that indicates how to change the value of that target element in order to change the objective variable to the target value. Specifically, it is shown that the objective variable can be changed to the target value by changing "ease of raising children" from "3.1" to "5.0," "waterside environment" from "4.1" to "4.5," and "green space area" from "2.5" to "3.5." This allows the user to recognize how to change the value of each target element in order to make the objective variable the target value.

In this example, the change in "ease of raising children" from "3.1" to "5.0" remains unchanged from the previous simulation. In other words, a prediction is made as to how much the "waterside environment" and "green area" should be changed in order to raise the "livability" by a further 0.6 after changing the "ease of raising children" from "3.1" to "5.0" and thereby raising the "livability" to "3.4." Of course, the simulation execution unit 209 may also change the way in which "ease of raising children" is changed. In this case, the simulation can be restarted from the beginning using the three target elements of "ease of raising children", "waterside environment", and "green area".

The element determination unit 207 may also automatically determine a target element to replace a target element when the objective variable does not reach the target value, or a target element to add when the objective variable does not reach the target value.

For example, the element determination unit 207 may determine an alternative or additional target element from among elements (those causally connected to the objective variable) not extracted by the element extraction unit 203, based on at least one of the degree of change in the objective variable when the value of the element is changed, the path coefficient of the path connecting the element and the objective variable, and the cost for changing the value of the element by a predetermined amount. In addition, in the above determination, the element determination unit 207 may also take into consideration whether or not the condition satisfaction determination unit 206 has determined that the element satisfies the condition.

An element that causes a large change in the objective variable when its value is changed is suitable as a target for changing its value in order to set the objective variable to a target value. Similarly, an element that has a large path coefficient for the path connecting the element and the objective variable, or an element that has a small cost for changing its value by a predetermined amount, is also suitable as a target for changing its value in order to set the objective variable to a target value. Therefore, by determining an alternative target element or an additional target element as described above, in addition to the effect achieved by the information processing device 1 according to the first exemplary embodiment, the effect of being able to present to the user suitable elements as targets for changing their values can be obtained.

The degree of change in the objective variable when the value of an element is changed is indicated by an index value calculated by the change index calculation unit 204. The path coefficient is calculated by the path coefficient calculation unit 205. Therefore, by using these index values, the element determination unit 207 can determine, as an alternative target element or an additional target element, an element that causes a large degree of change in the objective variable when its value is changed, or an element that has a large path coefficient for the path connecting the element and the objective variable.

Also, as described above, the cost for changing the value of each element by a specified amount can be specified in advance and stored in the storage unit 21 or the like. By using such data, the element determination unit 207 can determine elements that require a small cost to change as target elements to be substituted or added.

In addition, object a31 for accepting additions or changes to target elements may also display the modes in which the objective variable has reached the target value. This allows the user to perform simulations by arranging the elements that are automatically extracted according to the mode to their liking.

The element determination unit 207 may also rank the elements (those that are causally connected to the objective variable) that were not extracted by the element extraction unit 203. The ranking may be based on, for example, at least any one of the degree of change in the objective variable when the value of the element is changed, the path coefficient of the path connecting the element and the objective variable, the cost for changing the value of the element by a predetermined amount, and whether or not the condition satisfaction determination unit 206 has determined that the condition is satisfied.

The order may be determined so that elements suitable for changing the value are placed at the top. For example, the element determination unit 207 may rank the elements in descending order of the index value calculated by the change index calculation unit 204. The element determination unit 207 may also rank the elements based on multiple evaluation criteria. For example, the element determination unit 207 may assign points for each evaluation criterion, such as 10 points to the element with the lowest cost and 5 points to an element that the condition satisfaction determination unit 206 determines as satisfying the condition, and may determine the display order based on the total points.

By ranking the elements, the display control unit 208 can display each element according to the determined ranking and allow the user to select an element to be substituted or added from among the displayed elements.

(Flow of simulation method)
The flow of the simulation method according to this exemplary embodiment will be described with reference to Fig. 7. Fig. 7 is a flow diagram showing the flow of the simulation method. Note that Fig. 7 shows processing in a state where the causal analysis by the causal analysis unit 202 is completed and causal relationships between multiple elements are identified.

In S21, the reception unit 201 receives the designation of an element to be used as an objective variable in the simulation from among the multiple elements that have been causally analyzed, and the designation of a target value for that objective variable. Note that if the element to be used as an objective variable has been determined in advance, then the element may be made recognizable as an objective variable, for example by setting a flag on that element, and the reception of the designation of the objective variable may be omitted in S21. The reception unit 201 may also receive the designation of the simulation conditions, the designation of elements to be candidates for the target element, and the mode to be applied.

When accepting the designation of elements to be candidates for the target element, the processes of S26 to S29 may be performed for each of the elements that are causally linked to the objective variable. The display control unit 208 may then display the results of these processes as reference information for each element.

In addition, when accepting the designation of each element, the display control unit 208 may display a causal graph showing the relationships between each element that have been subjected to causal analysis. This allows the user to designate an element after recognizing the causal relationships between each element.

In S22, the element extraction unit 203 extracts one or more elements corresponding to each simulation mode from among the multiple elements that are causally linked to the target variable. If a mode is specified in S21, the element extraction unit 203 extracts elements corresponding to the specified mode.

In S23, the display control unit 208 displays the elements extracted in S22 for each mode as target elements whose values should be changed in order to change the objective variable to the target value.

In S24, the simulation execution unit 209 performs a simulation to calculate the value of each target element to bring the objective variable to the target value. The display control unit 208 then displays the calculated values. These values indicate how to change the values of the target elements to change the objective variable to the target value.

Note that the displays in S23 and S24 may be performed together. The display control unit 208 may also display the target element on the causal graph. In this case, the display control unit 208 may display the target element in a display mode that allows it to be distinguished from other elements. For example, the display control unit 208 may display the border of the node of the target element in a different display mode from that of the other nodes, as in the example of FIG. 4. The display control unit 208 may also display information on the causal graph that indicates how to change the value of the target element to change the objective variable to the target value.

In S25, the element determination unit 207 determines whether or not to add a target element. The criteria for determining whether or not to add a target element may be determined in advance. For example, the element determination unit 207 may determine to add a target element if there is a mode in the simulation performed in S24 in which the objective variable does not reach the target value. Also, for example, if there is a mode in the simulation performed in S24 in which the objective variable does not reach the target value, the display control unit 208 may display an object for adding a target element (such as object 31a shown in FIG. 6), and the element determination unit 207 may determine to add a target element when this object is selected.

In S26, the path coefficient calculation unit 205 calculates the path coefficient of the path connecting each element that is causally connected to the objective variable with the element that is set as the objective variable. Note that the weight value used to calculate the path coefficient can be calculated by known methods of causal inference or causal search.

In S27, the change index calculation unit 204 calculates an index value indicating the degree of change in the objective variable when the value of each element causally linked to the objective variable, i.e., the value of the explanatory variable, is changed. The path coefficient calculated in S26 is used to calculate the index value.

In S28, the condition satisfaction determination unit 206 determines whether or not each element that is causally linked to the objective variable satisfies a predetermined condition.

In S29, the element determination unit 207 identifies the cost of changing the value of each element that is causally linked to the objective variable by a specified amount.

In S30, the element determination unit 207 determines the target elements to be added based on the results of S26 to S29, and the display control unit 208 displays the determined target elements. Note that the element determination unit 207 does not necessarily need to use all of the results of S26 to S29. For example, the element determination unit 207 may determine the target elements to be added based on some or all of the results of S26 to S29 in accordance with the user's specifications.

In S31, the simulation execution unit 209 adds the target elements determined in S30 to the target elements applied in the simulation in S24, and performs a simulation to calculate the values of each target element to set the objective variable to a target value. The display control unit 208 then displays the calculated values. Note that the displays in S30 and S31 may be performed together. Similarly, it is also possible to determine a target element to be applied in place of the target element applied in the previous simulation, and perform a simulation using that target element. After S31 ends, the process returns to S25.

In S30, the element determination unit 207 may rank the elements causally linked to the objective variable based on some or all of the results of S26 to S29. The display control unit 208 may then display a list of the elements causally linked to the objective variable according to the above ranking, and allow the user to select the target element to be added.

[Modifications]
The execution subject of each process described in the above embodiment is arbitrary and is not limited to the above example. In other words, the functions of the information processing devices 1 and 2 can be realized by multiple devices (which can also be called processors) that can communicate with each other. For example, each process described in the flowcharts of Figures 2 and 7 can be shared and executed by multiple processors. In other words, the execution subject of the simulation method in the above embodiment may be one processor or multiple processors.

[Software implementation example]
Some or all of the functions of the information processing devices 1 and 2 may be realized by hardware such as an integrated circuit (IC chip), or may be realized by software.

In the latter case, the information processing devices 1 and 2 are realized, for example, by a computer that executes instructions of a program, which is software that realizes each function. An example of such a computer (hereinafter referred to as computer C) is shown in Figure 8. Computer C has at least one processor C1 and at least one memory C2. Memory C2 stores a program (simulation program) P for operating computer C as information processing device 1 or 2. In computer C, processor C1 reads and executes program P from memory C2, thereby realizing each function of information processing device 1 or 2.

The processor C1 may be, for example, a CPU (Central Processing Unit), GPU (Graphic Processing Unit), DSP (Digital Signal Processor), MPU (Micro Processing Unit), FPU (Floating point number Processing Unit), PPU (Physics Processing Unit), TPU (Tensor Processing Unit), quantum processor, microcontroller, or a combination of these. The memory C2 may be, for example, a flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination of these.

Computer C may further include a RAM (Random Access Memory) for expanding program P during execution and for temporarily storing various data. Computer C may further include a communications interface for sending and receiving data to and from other devices. Computer C may further include an input/output interface for connecting input/output devices such as a keyboard, mouse, display, and printer.

The program P can also be recorded on a non-transitory, tangible recording medium M that can be read by the computer C. Such a recording medium M can be, for example, a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit. The computer C can obtain the program P via such a recording medium M. The program P can also be transmitted via a transmission medium. Such a transmission medium can be, for example, a communications network or broadcast waves. The computer C can also obtain the program P via such a transmission medium.

[Additional Note 1]
The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims. For example, embodiments obtained by appropriately combining the technical means disclosed in the above-described embodiment are also included in the technical scope of the present invention.

[Additional Note 2]
Some or all of the above-described embodiments can be described as follows. However, the present invention is not limited to the aspects described below.

(Appendix 1)
An information processing device comprising: an element extraction means for extracting, for each mode of the simulation, one or more elements corresponding to a mode of the simulation from among a plurality of elements that are causally linked to the objective variable, in a simulation in which the value of one of the elements, an objective variable, is changed to a target value based on the results of a causal analysis of the plurality of elements; and a display control means for displaying, for each mode, the extracted elements as target elements whose values should be changed in order to change the objective variable to the target value.

(Appendix 2)
2. The information processing device according to claim 1, wherein the display control means displays information indicating how to change the value of the target element in order to change the objective variable to the target value.

(Appendix 3)
The information processing device according to claim 1 or 2, wherein the display control means, when changing the value of the displayed target element does not cause the objective variable to reach the target value, displays another element that is causally linked to the objective variable instead of or in addition to the target element.

(Appendix 4)
The information processing device according to claim 3, further comprising an element determination means for determining the other element from among the elements not extracted by the element extraction means, based on at least any of a degree of change in the objective variable when a value of the element is changed, a path coefficient of a path connecting the element and the objective variable, and a cost for changing the value of the element by a predetermined amount.

(Appendix 5)
The information processing device according to any one of appendixes 1 to 4, wherein the display control means displays, for each of a plurality of elements causally connected to the objective variable, at least one of an index value indicating the degree of change in the objective variable when the value of the element is changed, a path coefficient of a path connecting the element and the objective variable, and a cost for changing the value of the element by a predetermined amount, and the information processing device further comprises a reception means for receiving a selection of the plurality of elements causally connected to the objective variable, and the element extraction means extracts one or a plurality of elements including the element selected by the reception means.

(Appendix 6)
A simulation method comprising: in a simulation in which at least one processor changes a value of a target variable, which is one of multiple elements, to a target value based on the results of a causal analysis of multiple elements, extracting one or more elements corresponding to each mode of the simulation from among multiple elements that are causally linked to the target variable, and displaying the extracted elements for each mode as target elements whose values should be changed in order to change the target variable to the target value.

(Appendix 7)
A simulation program that causes a computer to function as: an element extraction means that extracts, for each mode of a simulation, from among a plurality of elements that are causally linked to a target variable, one of the elements, in a simulation in which the value of the target variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of the plurality of elements; and a display control means that displays, for each mode, the extracted elements as target elements whose values should be changed in order to change the target variable to the target value.

[Additional Note 3]
Some or all of the above-described embodiments can also be expressed as follows: An information processing device including at least one processor, which executes, in a simulation in which a value of a response variable, which is one of a plurality of elements, is changed to a target value based on a result of a causal analysis of the plurality of elements, a process of extracting, for each mode of the simulation, one or more elements corresponding to the mode from among a plurality of elements causally connected to the response variable, and a process of displaying, for each mode, the extracted elements as target elements whose values should be changed in order to change the response variable to the target value.

The information processing device may further include a memory, and the memory may store a program for causing the processor to execute the extraction process and the display process. The program may also be recorded on a computer-readable, non-transitory, tangible recording medium.

1 Information processing device 11 Element extraction unit (element extraction means)
12 Display control unit (display control means)
2 Information processing device 201 Reception unit (reception means)
203 Element extraction unit (element extraction means)
207 Element determining unit (element determining means)
208 Display control unit (display control means)

Claims (7)

an element extraction means for extracting, for each mode of the simulation, one or more elements corresponding to the mode from among the plurality of elements causally connected to the objective variable in a simulation in which a value of the objective variable, which is one of the elements, is changed to a target value based on a result of a causal analysis of the plurality of elements;
and a display control means for displaying the extracted elements for each of the modes as target elements whose values should be changed in order to change the objective variable to the target value. The information processing device according to claim 1, wherein the display control means displays information indicating how to change the value of the target element in order to change the objective variable to the target value. The information processing device according to claim 1 or 2, wherein the display control means, when changing the value of the displayed target element does not cause the objective variable to reach the target value, displays another element that is causally linked to the objective variable instead of or in addition to the target element. The information processing device according to claim 3, further comprising an element determination means for determining the other elements from among the elements not extracted by the element extraction means based on at least one of the degree of change in the objective variable when the value of the element is changed, the path coefficient of the path connecting the element and the objective variable, and the cost for changing the value of the element by a predetermined amount. the display control means displays, for each of a plurality of the elements causally connected to the objective variable, at least one of an index value indicating a degree of change in the objective variable when a value of the element is changed, a path coefficient of a path connecting the element and the objective variable, and a cost for changing the value of the element by a predetermined amount;
a receiving means for receiving a selection of a plurality of the elements that are causally connected to the objective variable,
The information processing apparatus according to claim 1 , wherein the element extracting means extracts one or a plurality of elements including the element selected by the accepting means. At least one processor
In a simulation in which a value of a response variable, which is one of the elements, is changed to a target value based on a result of a causal analysis of a plurality of elements, one or more elements corresponding to each mode of the simulation are extracted from among the plurality of elements that are causally linked to the response variable;
and displaying the extracted elements for each of the modes as target elements whose values should be changed in order to change the objective variable to the target value. Computer,
A simulation program that functions as follows: in a simulation in which the value of a dependent variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of multiple elements, the simulation program includes: an element extraction means that extracts, for each mode of the simulation, from among a plurality of elements that are causally linked to the dependent variable, one or more elements corresponding to the mode; and a display control means that displays, for each mode, the extracted elements as target elements whose values should be changed in order to change the dependent variable to the target value.

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