| The main research goal of this dissertation is to develop a model and a suite of instruments to evaluate the usability of academic digital libraries. Usability in this study was examined from the perspectives of effectiveness, efficiency, satisfaction, and learnability. The model that was developed considers both quantifying elements such as accuracy rate, time, and number of steps required to complete a task, and the subjective criterion, satisfaction, which is further broken down into the areas of ease of use, organization of information, terminology and labeling, visual appearance, content, and mistake recovery. The model was tested at two academic digital libraries. It is a cross-institutional usability study. The study recruited a total of forty-one subjects and was divided into two stages to confirm findings.; The study examined the interlocking relationships among effectiveness, efficiency, and satisfaction. It found that the relationships are statistically significant. The longer the time it took for a subject to perform a task, the more steps involved. The greater the number of steps involved in completing a task, the lower the satisfaction expressed by the subject. The longer the time spent on completing a task, the lower the satisfaction expressed by the subject. However, it should be noted that each criterion has its own emphasis and should be measured separately.; The research uncovered the user's criteria for ease of use, organization of information, terminology, visual attractiveness, and mistake recovery. The findings are helpful in enhancing the usability of the digital library.; The issues of "user lostness" and navigation disorientation were examined, and the causes were identified.; The study also examined the click cost issue. It found that 73% of the participants expected the click(s) to lead them eventually to the correct answer. Each click in the digital library should bring users closer to the answer.; The study established that the demographic factors (gender, age, status, academic major, ethnic background, years at the institution, and frequency of using library Web sites) do not have a statistically significant impact on performance (i.e., effectiveness and efficiency). However, different attitudes among ethnic groups were found in rating satisfaction. Future research should recruit more subjects in each ethnic group to examine this cross-culture usability issue further. |
