Problems of consolidating usability problems

The process of consolidating usability problems (UPs) is an integral part of usability evaluation involving multiple users/analysts. However, little is known about the mechanism of this process and its effects on evaluation outcomes, which presumably influence how developers redesign the system of interest. We conducted an exploratory research study with ten novice evaluators to examine how they performed when merging UPs in the individual and collaborative setting and how they drew consensus. Our findings indicate that collaborative merging causes the absolute number of UPs to deflate, and concomitantly the frequency of certain UP types as well as their severity ratings to inflate excessively. It can be attributed to the susceptibility of novice evaluators to persuasion in a negotiation setting, and thus they tended to aggregate UPs leniently. Such distorted UP attributes may mislead the prioritization of UPs for fixing and thus result in ineffective system redesign.