Long-Term Video QoE Assessment Studies: A Systematic Review

Although longitudinal studies are common in other disciplines, such as psychology, medicine, or User Experience, they are rarely used in Quality of Experience (QoE). However, observing users over time can provide useful information on the QoE and help to better understand its influencing factors. Here, we present a systematic review of the methodologies of longitudinal studies in the QoE domain. We review papers selected through a systematic search and discuss various aspects of described studies, such as methods of gathering subjective assessment or length of the studies. Our work recognizes common practices that can be used to reproduce and extend the proposed long-term study designs. Additionally, based on our review, we propose future work directions for the longitudinal QoE studies.