Quantifying subjective quality evaluations for mobile video watching in a semi-living lab context

This paper discusses results from an exploratory study in which Quality of Experience aspects related to mobile video watching were investigated in a semi-living lab setting. More specifically, we zoom in on usage patterns in a natural research context and on the subjective evaluation of high and low-resolution movie trailers that are transferred to a mobile device using two transmission protocols for video (i.e., real-time transport protocol and progressive download using HTTP). User feedback was collected by means of short questionnaires on the mobile device, combined with traditional pen and paper diaries. The subjective evaluations regarding the general technical quality, perceived distortion, fluentness of the video, and loading speed are studied and the influence of the transmission protocol and video resolution on these evaluations is analyzed. Multinomial logistic regression results in a model to estimate the subjective evaluations regarding the perceived distortion and loading speed based on objectively-measured parameters of the video session

Exploring effects of response biases in affect induction procedures

This study examined whether self-reports or ratings of experienced affect, often used as manipulation checks on the efficacy of affect induction procedures (AIPs), reflect genuine changes in affective states rather than response biases arising from demand characteristics or social desirability effects. In a between-participants design, participants were exposed to positive, negative and neutral images with valence-congruent music or sound to induce happy, sad and neutral mood. Half of the participants had to actively appraise each image whereas the other half viewed images passively. We hypothesised that if ratings of affective valence are subject to response biases then they should reflect the target mood in the same way for active appraisal and passive exposure as participants encountered the same affective stimuli in both conditions. We also tested whether the AIP resulted in mood-congruent changes in facial expressions analysed by FaceReader to see whether behavioural indicators corroborate the self-reports. The results showed that while participants’ ratings reflected the induced target valence, the difference between positive and negative AIP was significantly attenuated in the active appraisal condition, suggesting that self-reports of mood experienced after the AIP are not entirely a reflection of response biases. However, there were no effects of the AIP on FaceReader valence scores, in line with theories questioning the existence of cross-culturally and inter-individually universal behavioural indicators of affective states. Efficacy of AIPs is therefore best checked using self-reports

IMPULSE moment-by-moment test:An implicit measure of affective responses to audiovisual televised or digital advertisements

IMPULSE is a novel method for detecting affective responses to dynamic audiovisual content. It is an implicit reaction time test that is carried out while an audiovisual clip (e.g., a television commercial) plays in the background and measures feelings that are congruent or incongruent with the content of the clip. The results of three experiments illustrate the following four advantages of IMPULSE over self-reported and biometric methods: (1) being less susceptible to typical confounds associated with explicit measures, (2) being easier to measure deep-seated and often nonconscious emotions, (3) being better able to detect a broad range of emotions and feelings, and (4) being more efficient to implement as an online method.Published versio

Selecting films for sex research: Gender differences in erotic film preference

The official published version can be obtained from the link below.The aim of this study was to explore gender differences in sexual responsiveness to erotic films that had been selected for their differential appeal for men and women. A secondary objective was to identify variables that influence sexual arousal and explore whether these variables differ for men and women. Fifteen men (M age = 26 yrs) and 17 women (M age = 24 yrs) were presented with 20 film clips depicting heterosexual interactions, half of which were female- and the other half male-selected, and were asked to rate the clips on a number of dimensions. Overall, men found the film clips more sexually arousing than did the women. Gender differences in arousal were negligible for female-selected clips but substantial for male-selected clips. Furthermore, men and women experienced higher levels of sexual arousal to clips selected for individuals of their own gender. Cluster regression analyses, explaining 77% of the variance for male and 65% for female participants, revealed that men's sexual arousal was dependent upon the attractiveness of the female actor, feeling interested, and both imagining oneself as a participant and watching as an observer. For women, with all variables entered, only imagining oneself as a participant contributed to sexual arousal ratings. The findings suggest that how films are selected in sex research is an important variable in predicting levels of sexual arousal reported by men and women

Influence of affective image content on subjective quality assessment

Image quality assessment (IQA) enables distortions introduced into an image (e.g., through lossy compression or broadcast) to be measured and evaluated for severity. It is unclear to what degree affective image content may influence this process. In this study, participants (n=25) were found to be unable to disentangle affective image content from objective image quality in a standard IQA procedure (single stimulus numerical categorical scale). We propose that this issue is worthy of consideration, particularly in single stimulus IQA techniques, in which a small number of handpicked images, not necessarily representative of the gamut of affect seen in true broadcasting, and unrated for affective content, serve as stimuli

Subjective quality assessment of longer duration video sequences delivered over HTTP adaptive streaming to tablet devices

HTTP adaptive streaming facilitates video streaming to mobile devices connected through heterogeneous networks without the need for a dedicated streaming infrastructure. By splitting different encoded versions of the same video into small segments, clients can continuously decide which segments to download based on available network resources and device characteristics. These encoded versions can, for example, differ in terms of bitrate and spatial or temporal resolution. However, as a result of dynamically selecting video segments, perceived video quality can fluctuate during playback which will impact end-users' quality of experience. Subjective studies have already been conducted to assess the influence of video delivery using HTTP Adaptive Streaming to mobile devices. Nevertheless, existing studies are limited to the evaluation of short video sequences in controlled environments. Research has already shown that video duration and assessment environment influence quality perception. Therefore, in this article, we go beyond the traditional ways for subjective quality evaluation by conducting novel experiments on tablet devices in more ecologically valid testing environments using longer duration video sequences. As such, we want to mimic realistic viewing behavior as much as possible. Our results show that both video content and the range of quality switches significantly influence end-users' rating behavior. In general, quality level switches are only perceived in high motion sequences or in case switching occurs between high and low quality video segments. Moreover, we also found that video stallings should be avoided during playback at all times

Overcoming Cognitive and Motivational Barriers to Media Literacy: A Dual-Process Approach

In today\u27s fast-paced, hyper-mediated society, the ability to balance accuracy and efficiency is essential. Media literacy educational programs have arisen to meet this need and proliferated in recent years. Although the practice of media literacy is thriving, its underlying mechanisms are poorly understood and evidence of effectiveness is mixed (e.g., Bergsma & Carney, 2008). A social psychological perspective has the potential to illuminate previously overlooked variables and inform research and practice in this growing field. In particular, whereas media literacy efforts typically emphasize thorough processing of media messages, dual-process theories of persuasion (e.g., Eagly & Chaiken, 1993; Petty & Cacioppo, 1986) suggest this is not always realistic. When motivation or ability is compromised, individuals default to a low-effort processing mode, relying on peripheral cues or heuristics rather than carefully evaluating message arguments. In this mode, media messages can persuade unconsciously. Using a dual-process approach, the present research investigated how specific barriers to motivation (perceptions of personal invulnerability) and processing ability (emotion-based advertising, environmental distractions) influence the processes of media literacy. Participants (N = 882) were randomly assigned to 16 conditions in a 2 [vulnerability: demonstrated, control] x 2 [distractions: present, absent] x 2(2) [ad type: informational, emotional; two replicates of each type] between-subjects nested design. The vulnerability manipulation increased distrust in the target ads and reduced their persuasiveness, not through the hypothesized mechanism of heightened perceptions of vulnerability, but mediated by increased counterarguing. Relative to informational ads, emotional ads were judged more persuasive, attractive, similar to personal experience, and elicited greater identification. However, they were also rated less trustworthy than informational ads, suggesting emotional advertising largely bypasses logical decision-making processes. Distraction reduced counterarguing only among those who found the ad relatively unpersuasive. The results of this research highlight the central role of trust in media literacy processes. Although individuals recognize and distrust emotional forms of advertising, they are nonetheless persuaded by such appeals. Given the sophistication of contemporary advertising techniques and the ubiquity of distractions, the present research suggests new approaches to media literacy are needed, specifically tailored to decision-making under these more realistic media-use conditions

Sexual Arousal\u27s Effect on College Men\u27s Ability to Detect Protest in a Date Rape Analogue

This study evaluated the impact of sexual arousal on college men\u27s ability to identify when sexual advances should cease in response to protest depicted in a date-rape audio vignette. Participant arousal level was manipulated via exposure to one of three experimental videos: a neutral control video, a humor control video, or an erotic video clip. Participants provided subjective arousal levels. Participants then listened to an audio recording depicting conversation and mutual sexual activity escalating to rape. Response latency was obtained when participants indicated the male should refrain from making further sexual advances. Participant latency time did not significantly differ by condition. This potentially suggests that sexual arousal does not impact men\u27s ability to detect partner protest in a date rape situation