Erik Wästlund

Effects of VDT and paper presentation on consumption and production of information: Psychological and physiological factors

Two experiments were performed to investigate the influence of VDT (video display terminals) and paper presentation of text on consumption of information (Study 1) measured in the form of convergent production and production of information (Study 2) measured in form of divergent production. The READ test of reading comprehension was used as the convergent task whereas the “Headlines” test was used as the divergent task. Several other factors pertaining to performance were also studied including the PANAS test of positive and negative affect, the STH test of stress, tiredness and hunger, the TRI (Technology Readiness Inventory) and the SE test of stress and energy.The results show that performance in the VDT presentation condition where inferior to that of the Paper presentation condition for both consumption and production of information. Concomitantly, participants in the VDT presentation condition of the consumption of information study reported higher levels of experienced stress and tiredness whereas the participants in the VDT presentation condition of production of information study reported only slightly higher levels of stress.Although the results are discussed in both physiological and psychological terms arguments are made that the incremental effects of VDT text presentation stem mainly from dual-task effects of fulfilling the assignment and working with the computer resulting in a higher cognitive workload.

Internet Blues Revisited: Replication and Extension of an Internet Paradox Study

This study is a replication of the Kraut et al. Internet paradox study designed to set guidelines for harmless Internet usage, without any potential for personal damage. The present study produced two main results: The first is a partial confirmation of the general response pattern found by Kraut et al. (i.e., that younger individuals tend to use the Internet to a higher degree and that they experience a lesser degree of psychological well-being). The second main result, however, contradicts the interpretation by Kraut et al. of the causal relationship between Internet usage and psychological well-being.

Exploring Touch-Screen Biometrics for User Identification on Smart Phones

The use of mobile smart devices for storing sensitive information and accessing online services is increasing. At the same time, methods for authenticating users into their devices and online services that are not only secure, but also privacy and user-friendly are needed. In this paper, we present our initial explorations of the use of lock pattern dynamics as a secure and user-friendly two-factor authentication method. We developed an application for the Android mobile platform to collect data on the way individuals draw lock patterns on a touchscreen. Using a Random Forest machine learning classifier this method achieves an average Equal Error Rate (EER) of approximately 10.39%, meaning that lock patterns biometrics can be used for identifying users towards their device, but could also pose a threat to privacy if the users’ biometric information is handled outside their control.

The effect of page layout on mental workload: A dual-task experiment

In two dual-task experiments, the effects of page layout on mental workload were explored. Previous studies indicate that it is preferable to present a text document on paper than to display it on a computer screen (e.g. Mayes, D. K., Sims, V. K., & Koonce, J. M. (2001). Comprehension and workload differences for VDT and paper-based reading. International Journal of Industrial Ergonomics, 28(6), 367-378; Wastlund, E., Reinikka, H., Norlander, T., & Archer, T. (2005). Effects of VDT and paper presentation on consumption and production of information: Psychological and physiological factors. Computers in Human Behavior, 21, 377-394). However, critics have advocated improper matching of the materials between the two media as a confounding variable e.g. (Noyes, J. M., & Garland, K. J. (2003). VDT versus paper-based text: reply to Mayes, Sims and Koonce. International Journal of Industrial Ergonomics, 31(6), 411-423). The focus of the present study has been to take one such variable, page layout, and then isolate and replicate it onscreen in order to assess its affect on user performance. The results of the present experiments showed that optimizing the page layout for onscreen viewing decreased mental workload. This not only confirms the importance of matching all aspects of the presentational modes in doing paper vs. computer comparisons, but also shows that reading from a computer screen can be facilitated by creating documents with a page layout that is adapted to the screen which they are intended to be presented on.

Towards Usable Privacy Policy Display a Management

This paper discusses the approach taken within the PrimeLife project for providing user-friendly privacy policy interfaces for the PrimeLife Policy Language (PPL).We present the requirements, desig ...

Exploring Cross-Cultural Differences in Self-Concept: A Meta-Analysis of the Self- Description Questionnaire-1

This meta-analytic approach, designed to explore the cross-cultural differences in levels of self-concept as measured by the Self-Description Questionnaire, yielded two main results. (a) There seems to be a general pattern in self-concept amongst schoolchildren from the three cultural groups included in this investigation (i.e., Asia, Africa, and Australia/United States). Girls have higher or equal means in most academic areas and boys are higher in nonacademic and total self-concept. Furthermore, (b) in the comparison between these cultural groups a pattern emerged whereby the children from Africa, generally, had the most positive self-concept, the children from Asia had the least positive self-concept in the nonacademic subareas, and the children from Australia/United States had the least positive self-concept in the academic subareas. Because these differences are difficult to explain solely with the concepts of individualism and collectivism, a tentative explanation incorporating the concept of optimism is suggested.

What you see is where you go: testing a gaze-driven power wheelchair for individuals with severe multiple disabilities

Individuals with severe multiple disabilities have little or no opportunity to express their own wishes, make choices and move independently. Because of this, the objective of this work has been to develop a prototype for a gaze-driven device to manoeuvre powered wheelchairs or other moving platforms. The prototype has the same capabilities as a normal powered wheelchair, with two exceptions. Firstly, the prototype is controlled by eye movements instead of by a normal joystick. Secondly, the prototype is equipped with a sensor that stops all motion when the machine approaches an obstacle. The prototype has been evaluated in a preliminary clinical test with two users. Both users clearly communicated that they appreciated and had mastered the ability to control a powered wheelchair with their eye movements.

Trust and Assurance HCI

In this chapter, we present our HCI (Human Computer Interaction) work for mediating the degree of trustworthiness of services sides to end users and for enhancing their trust in PrimeLife-enabled applications. For this, we will present the user interface development work of a trust evaluation function and the PrimeLife Data Track.

Left isn't always right: placement of pictorial and textual package elements

The purpose of this study is to investigate how the positioning of textual and pictorial design elements on a package affects visual attention (detection time) toward these element types. The study ...

PET-USES: Privacy-Enhancing Technology Users' Self-Estimation Scale

This paper describes the “Privacy-Enhancing Technology Users’ Self-Estimation Scale (PET-USES)”, a questionnaire that enables users to evaluate PET user interfaces for their overall usability and to measure six different PET aspects. The PET-USES is intended to be used during usability testing and evaluation of PET user interfaces. The focus of the PET-USES is the subjective experience of the user rather than the intrinsic PET functionality of the application being tested. Although the test has been developed within the PrimeLife project to test the usability of PETs developed therein, the test is constructed in such a fashion that it should be applicable to a wide variety of PETs. The objective of this paper is to outline the creation and the background of the PET-USES questionnaire and invite the usability community not only to use the test, but also to contribute to the further development of the PET-USES.