Usability Testing and Heuristic Evaluation Essay

Usability Testing and Heuristic Evaluation - Essay Example Usability Testing and Heuristic Evaluation Learnability affects how fast a user can learn and use the system after undergoing a certain amount and duration of training. Efficiency affects the amount of tasks a user can perform in a set amount of time. Meanwhile, memorability enables a user to use the system after a period of inactivity without having to relearn its operation. Low error rate refers to the number of problems encountered by the user and the ease of correcting such errors. Lastly, satisfaction generally refers to the overall user perception of the system serving its intended purpose. Usability Testing The term usability testing has been generally referred to as any method used to evaluate a system or product. For the purpose of clarification, the term usability testing shall be used in this paper as a distinct empirical method of system evaluation with the goal of identifying usability issues and developing recommendation on how address such issues. Rubin and Chisnell described usability testing as a process of r ecruiting people as test participants to evaluate the system based on a series of usability guidelines. Test participants are normally composed of individuals whose profiles represent the target user audience. The inclusion of test participants based on real world parameters is what makes usability testing unique among other usability assessment methods. In this method, test participants are selected from the target user audience and are asked to perform specific tasks using a prototype of the system. During the duration of the test, user performance and reactions to the product are observed and recorded by a facilitator (Fiset, 2009). In essence, usability testing is a research tool which originated from conventional experimental methodology. The range of usability tests that can be performed is significantly broad, allowing the developer to tailor-fit approaches according to the test objectives, time constraints, and resources available (Rubin & Chisnell, 2008). Since it originate d from conventional approaches for controlled experiments, usability testing follows formal methods which include: (1) hypothesis formulation; (2) random sampling of participants; (3) utilization of experimental controls; (4) utilization of controlled groups; and (4) composition of sample size to determine statistical differences between groups (Rubin & Chisnell, 2008). Fiset (2009) outlined the following basic steps in conducting usability assessments: (1) definition of test objectives; (2) enumeration of tasks; (3) developing a prototype or mock-up of the system; (4) performing a preliminary validation test on prototype; (5) recruiting test participants; (6) preparing forms, venue, and equipment; (7) determining level of confidentiality of acquired data; (8) conducting the test proper; (9) filling out of evaluation questionnaire; (10) analysis and consolidation of results; (11) writing down of recommendations. The objectives of the usability test are normally determined by the pha se of system development the test will be carried out. Initial usability tests usually involve performing specific tasks based on the system design. As development progresses, additional objectives may be added such as identification of number errors, gauging user satisfaction, measuring time spent completing a

Comparing Vulnerability to Posttraumatic Stress Disorder among War Research Paper

Comparing Vulnerability to Posttraumatic Stress Disorder among War Veterans and the General Population and Gender Differences in Developing the Disorder - Research Paper Example This criterion was based on the fact that it would be almost impossible to get members of the general public who have been to battlefields, majorly because the number of such participants is merely restricted to victims of war, journalists, and aid workers all of who are deemed to comprise a very small proportion of the population. This decision was also motivated by the fact that in the present survey, none of the non-veteran participants indicated as having served in any warzones for any length of time. Using this criterion, the average length of time spent in warzones by the participants was 12.9 (std. dev. = 19.07) months. While some veteran participants had never been to warzones, the longest amount of time served in such regions by any of the participants was 60 months. Uncharacteristically, the standard deviation for this data is larger than the mean, implying that the rate of variation form the mean was particularly huge. The inferential tests were undertaken at the 5% level of significance. Ten out of the 13 participants diagnosed with PTSD were veterans, signifying that this group made up 76.92% of all cases of the condition diagnosed within the sample. The non-veterans were, therefore, more likely to fail the PTSD test, recording 13 (72.2%) of all failed PTSD tests. Using the ‘chitest’ function in Excel, the significance of associations between pairs of variables was assessed. The association between veteran status for individuals and PTSD prevalence was statistically significant (χ2 = 7.30, df = 1, p = 0.007). Clearly, the above result confirms the significance of the difference in the ratios indicated above, with the implication that the prevalence of PTSD was significantly higher among veterans than among the non-veterans. The Pearson chi square value for the association between PTSD status (either being diagnosed with the condition or failing to show signs for the same) and gender