Usability Guidelines for Product Recommenders Based on Example Critiquing Research

Over the past decade, our group has developed a suite of decision tools
based on example critiquing to help users find their preferred products in e-commerce
environments. In this chapter, we survey important usability research work relative
to example critiquing and summarize the major results by deriving a set of usabil-
ity guidelines. Our survey is focused on three key interaction activities between the
user and the system: the initial preference elicitation process, the preference revision
process, and the presentation of the systems recommendation results. To provide a
basis for the derivation of the guidelines, we developed a multi-objective frame-
work of three interacting criteria: accuracy, confidence, and effort (ACE). We use
this framework to analyze our past work and provide a specific context for each
guideline: when the system should maximize its ability to increase users’ decision
accuracy, when to increase user confidence, and when to minimize the interaction
effort for the users. Due to the general nature of this multi-criteria model, the set
of guidelines that we propose can be used to ease the usability engineering process
of other recommender systems, especially those used in e-commerce environments.
The ACE framework presented here is also the first in the field to evaluate the per-
formance of preference-based recommenders from a user-centric point of view.
Designers can use these guidelines for the implementation of an effective and
successful product recommender.