The use of mobile bar code scanners is expanding to markets beyond popular manufacturing uses, such as healthcare, environmental testing and professional services. The successful interaction of users with mobile bar code scanners is of great importance from a business and technology perspective as well as from the user standpoint. Interaction problems associated with these devices may cause errors in data collection and affect job performance due to frustration, resulting in a potential impact on internal costs. The primary objective of this research was to develop design guidelines for the reengineering of keyboard designs for mobile bar code scanners. A secondary objective was to determine the effectiveness of current bar code scanner designs and how they can be related to other mobile technologies to develop a link across research areas. To accomplish these objectives, three different mobile bar code scanner keyboard designs were investigated: multiple-alphabetical, single-alphabetical and single split-Qwerty. A total of 42 subjects (18 females and 24 males) were recruited to participate in the experiment that was conducted to validate the research hypotheses. Time and accuracy data were recorded during the experiment and workload/subjective questionnaires were given to each participant following interaction with the different mobile bar code scanners. The following conclusions were reached based on the experimental results and are considered the major contributions of this research. First, an alphabetically laid out keyboard with multiple keys results in more time to find a character, a higher percentage of time spent typing incorrect lines, and a higher error rate than an alphabetically laid out keyboard with single keys. Perceived workload was also higher for a keyboard with multiple keys versus one with single keys. Second, no significant differences were found in the time to find a character, the percentage of time spent typing incorrect lines, and the error rate between keyboards with single keys, whether they are laid out alphabetically or in a split-Qwerty design. Finally, training a user on how to use a specific mobile bar code scanner keyboard layout often results in higher character rates, less time spent typing incorrect lines, and a lower error rate. / Graduation date: 2006