Investigating the effects of test clip quality distribution in HD video Quality-of-Experience studies

A common guideline for Quality of Experience (QoE) testing is to present the whole range of low and high quality test clips in order to avoid rating biases. We present a comparative empirical study in the context of HD IPTV services, in which one group of participants exclusively viewed high-quality video clips, and the other group additionally were confronted with low-quality clips. We only found a very weak effect of clip quality distribution on rating behavior and thus cannot confirm the recommendation for including low-quality clips in HD video QoE evaluations.