This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2022-89085, filed on May 31, 2022, the entire contents of which are incorporated herein by reference.
The embodiment discussed herein is related to an accuracy determination technique.
In some cases, a machine learning model may be used for examination such as examination for loans or assist in the examination. However, as a result of training of the machine learning model with unfairly biased data, in some cases, for example, determination depending on the gender difference may be performed.
Accordingly, a fairness correction process for ensuring the fairness of determination by the machine learning model by excluding unfairly biased data is desired. In the fairness correction process, for example, training data is processed to retrain the machine learning model.
Japanese Laid-open Patent Publication No. 2021-012593, Japanese Laid-open Patent Publication No. 2021-149842, U.S. Patent Application Publication No. 2021/0304063, and U.S. Patent Application Publication No. 2020/0320429 are disclosed as related art.
According to an aspect of the embodiments, there is provided a non-transitory computer-readable recording medium storing a determination program for causing a computer to execute processing including: obtaining, based on a first plurality of pieces of data each of which includes a plurality of attributes, a second plurality of pieces of data generated by processing the first plurality of pieces of data in accordance with nonuniformity of the first plurality of pieces of data with reference to a first attribute of the plurality of attributes, each of the second plurality of pieces of data including data generated from a corresponding piece of data among the first plurality of pieces of data; calculating, for each attribute of the plurality of attributes, a processing amount based on a difference between each piece of data of the first plurality of pieces of data and a corresponding piece of data of the second plurality of pieces of data; identifying, from among the plurality of attributes, at least one second attribute for which the processing amount calculated is larger than or equal to a predetermined threshold; identifying a magnitude of contribution of the at least one second attribute, the magnitude of contribution indicating a degree how the at least one second attribute affects, the magnitude of contribution indicating a degree how the at least one second attribute affects an inference result obtained by a machine learning model in a case where the machine learning model performs inference in response to inputting data into the machine learning; and determining, based on the magnitude of the contribution, an influence degree that indicates a degree how the second plurality of pieces of data affect the machine learning model in a case where the machine learning model is trained by using the second plurality of pieces of data.
The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention.
The fairness correction process exerts influence on accuracy of machine learning. In machine learning based on data on which the fairness correction process is performed based only on the viewpoint of fairness, in some cases degradation of the accuracy of the machine learning model may occur.
In one aspect, an object is to indicate accuracy influence on a machine learning model due to a fairness correction process.
Hereinafter, embodiment examples of a determination program, a determination apparatus, and a method of determining according to an embodiment will be described in detail with reference to the drawings. The embodiment is not limited by the embodiment examples. The embodiment examples may be appropriately combined with each other as long as they do not contradict each other.
First, unfair determination by machine learning and a process for correcting the unfair determination are described.
With reference to the table on the left side of
Accordingly, as the fairness correction process, as illustrated in the table on the right side of
Although such a fairness correction process may correct unfair determination by the machine learning model, the fairness correction process is fundamentally processing of training data. Thus, there is a possibility that the accuracy of the machine learning model is degraded. Accordingly, for example, when the fairness correction process is performed during operation, the system using the machine learning model is significantly influenced.
Meanwhile, in a long-term operation of a system using the machine learning model, periodic retraining is desired to maintain the accuracy of the machine learning model. Thus, it is desired that the influence of the training data exerted on the accuracy of the existing machine learning model be small. The influence exerted on the accuracy of the machine learning model may be simply represented as influence exerted on the machine learning model, influence on the machine learning model, or the like. When the processing tendency illustrated in
However, referring to
[Functional Configuration of Determination Apparatus 10]
Next, a functional configuration of a determination apparatus 10 that is an operating subject according to the present embodiment is described.
For indicating the accuracy influence on the machine learning model, the determination apparatus 10 identifies the model contribution degree of the attribute processed with a large processing amount identified from the difference between the input data and the correction data and determines, based on the model contribution degree, the influence degree in a case where the machine learning model is trained. The determination apparatus 10 includes a model storage unit 11, a classification unit 12, a correction unit 13, an identification unit 14, a determination unit 15, and a training unit 16.
The model storage unit 11 stores, for example, the machine learning model. For example, the model storage unit 11 stores parameters of a neural network of the machine learning model. The parameters include weights between neurons. The weights between neurons are updated by machine learning.
For example, the classification unit 12 uses the machine learning model stored in the model storage unit 11 to classify the correction data generated by converting, with the correction unit 13, the input data and outputs as an inference result of the machine learning model.
For example, as illustrated in the table on the right side of
Based on the difference between the input data and the correction data obtained by processing the input data based on the nonuniformity of the input data with reference to a first attribute out of a plurality of the attributes, the identification unit 14 identifies a second attribute processed with a processing amount larger than or equal to a predetermined threshold out of the plurality of attributes. The first attribute and the second attribute may be the protected attributes. The input data corresponds to a first plurality of pieces of data, and the correction data corresponds to a second plurality of pieces of data obtained by processing the first plurality of pieces of data, for example, performing the correction process on the first plurality of pieces of data. The second attribute processed with a processing amount larger than or equal to the predetermined threshold out of the plurality of attributes may be, for example, one or a plurality of second attributes, in descending order, with a processing amount larger than or equal to the predetermined threshold out of the plurality of attributes.
The identification unit 14 identifies, for example, the magnitude of contribution of the second attribute to the inference result in a case where the classification unit 12 inputs the correction data and the machine learning model performs inference.
The determination unit 15 determines, for example, the influence degree based on the magnitude of the contribution identified by the identification unit 14 in a case where the machine learning model is trained with the correction data.
For example, the training unit 16 retrains the machine learning model stored in the model storage unit 11 by using the correction data selected based on the influence degree determined by the determination unit 15 and updates the machine learning model. The selected correction data is, for example, data on which processing that is good for the machine learning model is performed, in which the mainly processed attributes have a high contribution degree to the machine learning model, and which is entirely processed.
[Details of Functions]
Next, determination on the influence on the machine learning model executed by the determination apparatus 10 (hereafter, may be referred to as “model influence” in some cases) is described in more detail.
As illustrated in the lower left part of
As illustrated on the right side of
Contribution Degree Rank=Σn=1num(Rank−1*Count) (1)
In Expression (1), for each of the predetermined number of the attributes extracted in descending order, for example, num is a number indicating the attribute, Rank indicates the rank of the model contribution degree of the attribute, and Count indicates the number of pieces of data counted for the attribute.
Based on the variance value of the correction data and the contribution degree rank, the determination apparatus 10 determines the model influence degree. The model influence degree is determined by, for example, mapping the model influence degree from the variance value of the correction data and the contribution degree rank.
The determination apparatus 10 may select, from among various types of correction data, candidates for the correction data to be used for training of the machine learning model based on a fairness score by the fairness correction process, prediction accuracy of the machine learning model, and the model influence score.
The fairness score by the fairness correction process is, for example, a DI score that is an example of the fairness score and may be calculated by dividing the incidence of protected attribute value (for example, gender=female) to be watched carefully and an arbitrary determination result X by the incidence of the other determination results X. The prediction accuracy of the machine learning model is, for example, an evaluation index of an existing technique, for example, accuracy (correct answer rate) and may be calculated by dividing the number of correct answers in a case where the input data is input to the machine learning model by the number of all pieces of the input data. The model influence score may be calculated, for example, by the following expression: “model influence score=(α×1/variance value+β×contribution degree rank)”. In the above-described expression, α and β are weight parameters for the variance value and the contribution degree rank, respectively.
As illustrated in
[Flow of Process]
Next, with reference to
First, as illustrated in
Next, for each of the correction plans, the determination apparatus 10 calculates the variance value based on the difference amount between the corresponding correction data and the input data (step S102).
Next, for each of the correction plans, the determination apparatus calculates the processing intensity based on the difference amount between the corresponding correction data and the input data, thereby identifying the attributes strongly processed with the processing intensity larger than or equal to a certain value (step S103). The attributes processed with the processing intensity larger than or equal to a certain value may be, for example, a predetermined number, in descending order, of the attributes processed with the processing intensity larger than or equal to a predetermined threshold selected.
Next, for each of the correction plans, the determination apparatus calculates the model contribution degree of the attributes identified in step S103 (step S104).
Next, for each of the correction plans, the determination apparatus calculates the contribution degree rank based on the model contribution degree calculated in step S104 (step S105).
Next, for each of the correction plans, the determination apparatus outputs the model influence degree based on the variance value calculated in step S102 and the contribution degree rank calculated in step S105 (step S106). The output of the model influence degree may be, for example, mapping of the model influence degree based on the variance value and the contribution degree rank as illustrated in
[Effects]
As described above, the determination apparatus 10 identifies, based on a difference between a first plurality of pieces of data and a second plurality of pieces of data obtained by processing the first plurality of pieces of data based on nonuniformity of the first plurality of pieces of data with reference to a first attribute out of a plurality of attributes, at least one second attribute processed with a processing amount larger than or equal to a predetermined threshold out of the plurality of attributes. The determination apparatus 10 also identifies a magnitude of contribution of the at least one second attribute to an inference result in a case where data is input and a machine learning model performs inference. The determination apparatus 10 determines, based on the magnitude of the contribution, an influence degree in a case where the machine learning model is trained by using the second plurality of pieces of data.
As described above, the determination apparatus 10 identifies the model contribution degree of the attribute processed with a large processing amount identified from the difference between the input data and the correction data and determines, based on the model contribution degree, the influence degree in training. Thus, the determination apparatus 10 may indicate the accuracy influence on the machine learning model due to the fairness correction.
In the process of identifying the at least one second attribute executed by the determination apparatus 10, the at least one second attribute includes a plurality of second attributes. The process of identifying the at least one second attribute includes a process of identifying, based on the difference between the second plurality of pieces of data and the first plurality of pieces of data, one or the plurality of second attributes processed with processing amounts larger than or equal to the predetermined threshold in descending order out of the plurality of attributes.
Thus, the determination apparatus 10 may indicates the accuracy influence on the machine learning model due to the fairness correction only for the attributes processed with a larger processing amount.
[System]
Unless otherwise specified, processing procedures, control procedures, specific names, and information including various types of data and parameters described in the above description or the drawings may be arbitrarily changed. The specific examples, distributions, numerical values, and so forth described in the embodiment examples are merely exemplary and may be arbitrarily changed.
The specific form of distribution or integration of elements included in the determination apparatus 10 is not limited to that illustrated in the drawings. For example, the classification unit 12 of the determination apparatus may be distributed to a plurality of processing units, or the correction unit 13 and the identification unit 14 of the determination apparatus 10 may be integrated into a single processing unit. For example, all or part of the elements may be configured so as to be functionally or physically distributed or integrated in arbitrary units in accordance with various types of loads, usage states, or the like. All or an arbitrary subset of the processing functions performed by the apparatus may be realized by a central processing unit (CPU) and a program analyzed and executed by the CPU or may be realized by hardware using wired logic.
The communication interface 10a is a network interface card or the like and communicates with an information processing apparatus. The HDD 10b stores, for example, the program and data that cause the functions illustrated in, for example,
Examples of the processor 10d include a CPU, a microprocessor unit (MPU), a graphics processing unit (GPU), and the like. Alternatively, the processor 10d may be realized by an integrated circuit such as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). For example, the processor 10d reads, from the HDD 10b or the like, a program that executes processes similar to the processes performed by the processing units illustrated in, for example,
The determination apparatus 10 may also realize the functions similar to the functions of the above-described embodiment examples by reading out the above-described program from a recording medium with a medium reading device and executing the above-described read program. The program described in the embodiment examples is not limited to the program to be executed by the determination apparatus 10. For example, the above-described embodiment examples may be similarly applied in a case where an information processing apparatus executes the program or in a case where the information processing apparatus and the determination apparatus 10 cooperate with each other to execute the program.
The program may be distributed via a network such as the Internet. The program may be recorded in a computer-readable recording medium such as a hard disk, a flexible disk (FD), a compact disc read-only memory (CD-ROM), a magneto-optical (MO) disk, or a Digital Versatile Disc (DVD). The program may be executed by being read from the recording medium by the determination apparatus 10 or the like.
The following appendices are further disclosed in relation to the embodiment including the embodiment examples described above.
All examples and conditional language provided herein are intended for the pedagogical purposes of aiding the reader in understanding the invention and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although one or more embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.
Number | Date | Country | Kind |
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2022-089085 | May 2022 | JP | national |