Explanations in Everyday Software Systems: Towards a Taxonomy for Explainability Needs

TL;DR

This paper develops a taxonomy of explainability needs for various software systems based on a survey, aiming to guide the integration of explanations in software design to improve understandability.

Contribution

It introduces a novel taxonomy of explainability needs applicable across different software types, derived from empirical survey data.

Findings

Identified 315 explainability needs from user statements.

Classified explainability needs into a comprehensive taxonomy.

Showed how explainability needs vary across software types.

Abstract

Modern software systems are becoming increasingly complex and opaque. The integration of explanations within software has shown the potential to address this opacity and can make the system more understandable to end-users. As a result, explainability has gained much traction as a non-functional requirement of complex systems. Understanding what type of system requires what types of explanations is necessary to facilitate the inclusion of explainability in early software design processes. In order to specify explainability requirements, an explainability taxonomy that applies to a variety of different software types is needed. In this paper, we present the results of an online survey with 84 participants. We asked the participants to state their questions and confusions concerning their three most recently used software systems and elicited both explicit and implicit explainability needs from their statements. These needs were coded by three researchers. In total, we identified and classified 315 explainability needs from the survey answers. Drawing from a large pool of explainability needs and our coding procedure, we present two major contributions of this work: 1) a taxonomy for explainability needs in everyday software systems and 2) an overview of how the need for explanations differs between different types of software systems.