Pervasive and standalone computing: The perceptual effects of variable multimedia quality.

The introduction of multimedia on pervasive and mobile communication devices raises a number of perceptual quality issues, however, limited work has been done examining the 3-way interaction between use of equipment, quality of perception and quality of service. Our work measures levels of informational transfer (objective) and user satisfaction (subjective)when users are presented with multimedia video clips at three different frame rates, using four different display devices, simulating variation in participant mobility. Our results will show that variation in frame-rate does not impact a user’s level of information assimilation, however, does impact a users’ perception of multimedia video ‘quality’. Additionally, increased visual immersion can be used to increase transfer of video information, but can negatively affect the users’ perception of ‘quality’. Finally, we illustrate the significant affect of clip-content on the transfer of video, audio and textual information, placing into doubt the use of purely objective quality definitions when considering multimedia presentations

Children searching information on the Internet: Performance on children's interfaces compared to Google

Children frequently make use of the Internet to search for information. However, research shows that children experience many problems with searching and browsing the web. The last decade numerous search environments have been developed, especially for children. Do these search interfaces support children in effective information-seeking? And do these interfaces add value to today’s popular search engines, such as Google? In this explorative study, we compared children’s search performance on four interfaces designed for children, with their performance on Google. We found that the children did not perform better on these interfaces than on Google. This study also uncovered several problems that children experienced with these search interfaces, which can be of use for designers of future search interfaces for children

A potential application of pupillometry in web-usability research

Despite the increasing popularity of eye tracking technique, measurement of changes in pupil diameter has received considerably less attention. However, for over two millennia it is unambiguous, by studies of acclaimed researchers (Eckhard Hess, Michel Pierre Janisse or Lowenstein and Loewenfeld) that cognitive and emotional brain activities are in connection with pupil size changes. The area, evolved by their profound and comprehensive research is referred as pupillometry. Current review describes a potential application of pupillometry in web-usability research by applying ASL Mobile Eye device

Effects of User Age on Smartphone and Tablet Use, Measured with an Eye-Tracker via Fixation Duration, Scan-Path Duration, and Saccades Proportion

The design of user interfaces plays an important role in human computer interaction, especially for smartphones and tablet devices. It is very important to consider the interface design of smartphones for elderly people in order for them to benefit from the variety applications on such devices. The aim of this study is to investigate the effects of user age as well as screen size on smartphone/tablet use. We evaluated the usability of smartphone interfaces for three different age groups: elderly age group (60+ years), middle age group (40-59 years) and younger age group (20-39 years). The evaluation is performed using three different screen sizes of smartphone and tablet devices: 3.2", 7", and 10.1" respectively. An eye-tracker device was employed to obtain three metrics: fixation duration, scan-path duration, and saccades amplitude. Two hypothesis were considered. First, elderly users will have both local and global processing difficulties on smartphone/tablet use than other age groups. Second, all user age groups will be influenced by screen sizes; small screen size will have smaller saccades proportion indicating uneasy interface browsing compared to large screen size. All these results have been statistically evaluated using 2-way ANOVA

Analyzing the Impact of Cognitive Load in Evaluating Gaze-based Typing

Gaze-based virtual keyboards provide an effective interface for text entry by eye movements. The efficiency and usability of these keyboards have traditionally been evaluated with conventional text entry performance measures such as words per minute, keystrokes per character, backspace usage, etc. However, in comparison to the traditional text entry approaches, gaze-based typing involves natural eye movements that are highly correlated with human brain cognition. Employing eye gaze as an input could lead to excessive mental demand, and in this work we argue the need to include cognitive load as an eye typing evaluation measure. We evaluate three variations of gaze-based virtual keyboards, which implement variable designs in terms of word suggestion positioning. The conventional text entry metrics indicate no significant difference in the performance of the different keyboard designs. However, STFT (Short-time Fourier Transform) based analysis of EEG signals indicate variances in the mental workload of participants while interacting with these designs. Moreover, the EEG analysis provides insights into the user's cognition variation for different typing phases and intervals, which should be considered in order to improve eye typing usability.Comment: 6 pages, 4 figures, IEEE CBMS 201

Think aloud: Can eye tracking add value in detecting usability problems?

The protocols of Think Aloud and Eye Tracking, in their own unique way have proven to be great methods to understand users\u27 thought processes, and their mental models when interacting with interfaces. However the effectiveness of the combination of the two protocols in discovering usability problems has not been explored. This study aimed to discover if the addition of Eye Tracking data (fixations and scan movements) to the traditional protocol of Think Aloud can uncover more usability problems. Web users were split into three groups: Eye Tracking Only (ET), Think Aloud Only (TA), and Eye Tracking and Think Aloud Only (ET+TA). Participants in all conditions were asked to complete two tasks on two websites each. Along with questionnaires, eye movement data was collected for conditions with the Eye Tracking aspect and verbalizations were collected for conditions with the Think Aloud aspect. The analysis of the data showed that the total number of usability problems (not unique) identified by the participants in the `Eye Tracking and Think Aloud\u27 (ET + TA) condition was higher than the other two conditions. However, a Tukey HSD post-hoc test revealed that the differences between `ET + TA\u27 and the `Eye Tracking Only\u27 (ET) conditions was non-significant. The analysis also which resulted in non-significant differences between the conditions `Eye Tracking\u27 (ET) and `Eye Tracking and Think Aloud\u27 (ET + TA) led to inconclusive results on whether the Think Aloud method is disruptive or not. This may lead future researchers to develop robust practice sessions to help participants verbalize and create evaluation rules for eye movement data