In traditional subjective video quality experiments, the presented sequences are short and quality ratings are based on a single interaction with a service (i.e., one session). However, in real-life scenarios, users interact with a video service for a longer period of time. If decisions are made, such as to abandon a service, they are formulated based on longitudinal multi-episodic interaction. Therefore, it is important to better understand how quality is perceived in a longer interaction and how quality perception is linked to behavioral implications. My PhD work encompasses a longitudinal study of users’ interactions with a video service using a mobile device. In our study, which consists of six phases, we use different study designs to investigate how users perceive quality in a more ecologically valid setting. The study is carried out using a previously validated setup, which consists of compression software and a mobile application.

Recently an impressive development in immersive technologies, such as Augmented Reality (AR), Virtual Reality (VR) and 360${^\circ }$video, has been witnessed. However, methods for quality assessment have not been keeping up. This paper studies quality assessment of 360${^\circ }$video from the cross-lab tests (involving ten laboratories and more than 300 participants) carried out by the Immersive Media Group (IMG) of the Video Quality Experts Group (VQEG). These tests were addressed to assess and validate subjective evaluation methodologies for 360${^\circ }$video. Audiovisual quality, simulator sickness symptoms, and exploration behavior were evaluated with short (from 10 seconds to 30 seconds) 360${^\circ }$sequences. The following factors’ influences were also analyzed: assessment methodology, sequence duration, Head-Mounted Display (HMD) device, uniform and non-uniform coding degradations, and simulator sickness assessment methods. The obtained results have demonstrated the validity of Absolute Category Rating (ACR) and Degradation Category Rating (DCR) for subjective tests with 360${^\circ }$videos, the possibility of using 10-second videos (with or without audio) when addressing quality evaluation of coding artifacts, as well as any commercial HMD (satisfying minimum requirements). Also, more efficient methods than the long Simulator Sickness Questionnaire (SSQ) have been proposed to evaluate related symptoms with 360${^\circ }$videos. These results have been instrumental for the development of the ITU-T Recommendation P.919. Finally, the annotated dataset from the tests is made publicly available for the research community.

During the Covid-19 pandemic, the use of videoconferencing for medical consultations between patients and general practitioners (GPs) has strongly increased. The aim of this work-in-progress paper is to investigate which factors (technical and non-technical) influence patients' and doctor's Quality of Experience with video consultations (“tele-consultations”) and how. We report on findings from an online questionnaire (N=109) and an (ongoing) semi-structured interview study targeting GPs (N=4), highlighting the importance of both technical and nontechnical factors.