ABSTRACT

1. THE ROLE OF AUDIOVISUAL QUALITY IN MOBILE TELEVISION Satu Jumisko-Pyykkö, Kaisa Väänänen-Vainio-Mattila {@tut.fi,} Tampere University of Technology, Institute of Human-Centered Technology ABSTRACT Audiovisual quality is an important factor in acceptance and success of new mobile services such as mobile television. The produced quality is always a combination of the development of content and service providers, as well as handset manufacturers. The end result is perceived as a unity by the end users. Audiovisual quality effects consumers’ technology acceptance and adoption of new products. The quality requirements vary between different consumer groups, their needs for contents and usage contexts. The perception of quality is a combination of sensorial, cognitive, emotional and social factors. In this paper, we present how the presented quality factors and requirements can be applied in different levels of subjective quality research. The proposed model sets a framework for testing the complete set of user acceptance criteria of mobile TV audiovisual quality experience. SUBJECTIVE AUDIOVISUAL QUALITY In mobile TV products is affected by many players in the field (e.g. content, service providers, device manufactures) In technology acceptance model (TAM): (Davis et al. 1989, Venkatesh & Davis 2000) AV - quality as output quality factor  user’s trust toward the system and willingness to use new technology (Kaasinen 2005) • GOAL – to give • Holistic view to subjective audiovisual quality factors -Framework for quality of experience measurements connected to users, contents, contexts in the early stages of product development How to take into account quality factors in different stages of subjective testing in order to investigate the acceptance as early as possible in product development? Quality optimization assessment Usability testing Psychophysical assessment • Measurements of quality • Experience factors: • Cognitive e.g. information assimilation • Emotion e.g. affectiveness • Social e.g. attitude Potential users Potential contents Potential usage contexts Degree of the product readyness • QUALITY REQUIREMENTS OF MOBILE TV • FOR CONSUMPTION: • -Adoption from innovators and early adopters and to mainstream population (Moore 2002, Rogers 2003) • -Quality evaluations: • -Innovators and early adopters optimistic • -The younger participant the higher quality requirements (age variation: 18-65) (Ilvonen & Jumisko-Pyykkö 2005) • -Potential user selection: Attitude, age • FOR CONTENT: • Goals: To become informed and to be entertained (Casey et al. 2002) • Popular TV contents popular mobile TV contents: news, sport, TV series(Södergård et al. 2003) • Short watching times: less than 10 min • Quality evaluations with TV contents: • Content dependency e.g. AV bitrate ratio(Jumisko-Pyykkö & Häkkinen 2005) • Recognition of content and interest in the content • (Jumisko et al. 2005) -Potential content selection: TV content as stimuli material selected parallel to technical criteria • FOR CONTEXT: • Usage contexts: public transport vehicles, home, work place (Knoche & McCarthy 2005) • Contextual quality evaluations: not published • scenario of quality variations: bus stop–bus–bus stop • -Potential context selection: Context tests parallel to laboratory tests (Qualitative and quantitative research methods) FROM PERCEIVED TO EXPERIENCED QUALITY Quality of experience = overall degree in excellence how the system fills the requirements based on perceptual processes Satisfaction =preference Quality of Perception = satisfaction, information assimilation (Ghinea & Thomas 1998) Quality of Experience = sensorial layer, perceptual layer, emotional layer (Pereira 2005) • QoE MEASUREMENTS • What are the most important factor? • New definition for quality • Qualitative and quantitative approach • 2. What are the relations between the factors? • e.g xSensorial+yCognitive+zEmotional+vSocial • 3. Proper research method combinations • Cognitive: information recall about presented seen material • >> What was the result of the match? • Emotional: • >> How entertaining was the watched content? • Social: • >> How pleasant was watching while waiting the bus?