The Effects of Different Presentation Modalities on a Person Identification Task: A Study of Wireless Multimedia PDA Use in a Security Context

Abstract

The convergence of affordable multimedia capabilities with local and wide area wireless data networking on handheld devices is a particularly important trend. Using off-the-shelf technology, we conducted a simple experiment that required participants to engage in a person-identification task while posing as security agents in a field setting. Participants attempted to identify a target person in a public setting under different conditions with or without the aid of video information distributed to them via wireless-enabled multimedia PDAs. We developed a research framework and expectations based on previous research in the areas of the dual processing theory of working memory, information richness theory, and the role of video in grounding. Our findings suggest that dual modes of presentation (i.e., phonological and visuospatial information) simultaneously incorporated by a specific presentation significantly influence user perception and enhance task performance.

The authors thank Michigan State University, which supported this work through an Intramural Research Grant as well as through the MSU CyberSecurity Initiative. The authors thank Zoo H. Chae, Peter Murray, Christiana Sargent, and Amar Shool for their assistance in the field experiment. We also thank the management of the mall that hosted this study for their cooperation.

Notes

¹For a look at the many types of applications and services under consideration and in early trials, visit such Web sites and blogs as Multimedia Messaging.com (http://www.multimediamessaging.com), Picturephoning.com (http://textually.org/picturephoning), and MobileMMS.com (http://www.mobilemms.com).

²For example, law enforcement agents are using camera phones to send photos of offenders or missing children for quick identification on the scene and there have been numerous reports of citizens using camera phones to capture crimes in progress (CBSNews, 2003).

³Wi-Fi (or wireless fidelity) is a trademarked name from the Wireless Broadband Alliance that refers to equipment compatible with the IEEE 802.11b (11 Mbps transmission rate) wireless local area networking standard. We used a base station and external booster antenna to provide signal coverage throughout a corridor in the mall.

⁴For the field experiment, we used SONY PEG-NZ90 CLIE PDA devices with wireless LAN (802.11b) card. This latest model has lot of built-in multimedia communication features including a Bluetooth module for cable-free communication, a 2-megapixel camera supporting UXGA resolution for high-quality still photos, video recording (MPEG-4) and playback, an MP3 audio player, etc. The device also has 64k TFT color display with 480 × 320 pixels resolution and 3.9-inch touch screen.

⁵One participant was previously acquainted with the target and dropped from the analysis.

⁶In order to minimize delays from downloading and opening the video clip, we prestored it on the PDA. We recognize that download delays would have made the task more realistic and provided a fairer test but found that the operating system was not quite user-friendly enough to avoid artificial delays for this task.