Towards the Identifiability and Explainability for Personalized Learner Modeling: An Inductive Paradigm

TL;DR

This paper introduces ID-CDF, a new framework for personalized learner modeling that enhances identifiability and explainability by using an inductive, response-based paradigm, improving diagnosis accuracy without overfitting.

Contribution

The paper proposes a novel response-proficiency-response paradigm and an inductive learning framework to improve identifiability and explainability in cognitive diagnosis models.

Findings

ID-CDF effectively addresses non-identifiability and overfitting issues.

ID-CDF maintains diagnosis accuracy across diverse datasets.

The framework enhances interpretability of learner cognitive states.

Abstract

Personalized learner modeling using cognitive diagnosis (CD), which aims to model learners' cognitive states by diagnosing learner traits from behavioral data, is a fundamental yet significant task in many web learning services. Existing cognitive diagnosis models (CDMs) follow the proficiency-response paradigm that views learner traits and question parameters as trainable embeddings and learns them through learner performance prediction. However, we notice that this paradigm leads to the inevitable non-identifiability and explainability overfitting problem, which is harmful to the quantification of learners' cognitive states and the quality of web learning services. To address these problems, we propose an identifiable cognitive diagnosis framework (ID-CDF) based on a novel response-proficiency-response paradigm inspired by encoder-decoder models. Specifically, we first devise the diagnostic module of ID-CDF, which leverages inductive learning to eliminate randomness in optimization to guarantee identifiability and captures the monotonicity between overall response data distribution and cognitive states to prevent explainability overfitting. Next, we propose a flexible predictive module for ID-CDF to ensure diagnosis preciseness. We further present an implementation of ID-CDF, i.e., ID-CDM, to illustrate its usability. Extensive experiments on four real-world datasets with different characteristics demonstrate that ID-CDF can effectively address the problems without loss of diagnosis preciseness.