Visual or Textual: Effects of Explanation Format and Personal Characteristics on the Perception of Explanations in an Educational Recommender System

TL;DR

This study compares visual and textual explanations in an educational recommender system, revealing that well-designed visual explanations generally enhance user perception regardless of personal characteristics.

Contribution

It provides empirical evidence on how explanation formats and user traits jointly influence perceptions in educational recommender systems, offering design guidelines.

Findings

Visual explanations improve perceived control, transparency, trust, and satisfaction.

Design quality of visual explanations is crucial for effectiveness.

User traits have limited moderating effects on perception.

Abstract

Explanations are central to improving transparency, trust, and user satisfaction in recommender systems (RS), yet it remains unclear how different explanation formats (visual vs. textual) are suited to users with different personal characteristics (PCs). To this end, we report a within-subject user study (n=54) comparing visual and textual explanations and examine how explanation format and PCs jointly influence perceived control, transparency, trust, and satisfaction in an educational recommender system (ERS). Using robust mixed-effects models, we analyze the moderating effects of a wide range of PCs, including Big Five traits, need for cognition, decision making style, visualization familiarity, and technical expertise. Our results show that a well-designed visual, simple, interactive, selective, easy to understand visualization that clearly and intuitively communicates how user preferences are linked to recommendations, fosters perceived control, transparency, appropriate trust, and satisfaction in the ERS for most users, independent of their PCs. Moreover, we derive a set of guidelines to support the effective design of explanations in ERSs.