What is the relationship between task-based and open-ended usability testing, in terms of measuring satisfaction?

Abstract: Usability is one of the most important aspects of Information Technology. Usability plays a vital role in this industry, where organizations thrive to ensure utmost satisfaction of their end-users in regard to the experience of using their product. The systems may be a website or a software application. To measure user satisfaction, the method of usability testing can be performed. Performing usability testing gives a clear picture of difficulties that would be faced by potential target users. There are different types of usability testing such as Task-based usability testing, open ended usability testing, remote usability testing etc. The important point here is about deciding upon the most appropriate type of testing technique to get the accurate user satisfaction level. This study is mainly focused to answer the following research question: What is the relationship between the task-based and open ended usability testing, in terms of measuring satisfaction? System Usability Scale (SUS) has been used to measure the satisfaction of the users in this study. For this we used two websites performing task-based usability testing and open ended usability testing respectively. This study had involved twenty eight different participants. Participants are divided into two groups, one group to perform open ended usability testing and another for task-based usability testing for both the websites. This study has produced following results; Open-ended testing tended to produce higher SUS-ratings for the tested system. The results in this study showed that users performing open-ended usability testing gave positive responses for both the websites in terms of user satisfaction. Open-ended usability testing is an exploratory testing, where the testing is based on different aspects such as user interface of the system, design etc. Task-based usability testing is goal based where users have to complete the given task without fail. This method drew lower scores when compared to open-ended usability testing for the tested systems from the attained results. Nevertheless that task-based testing attained lower SUS scores, it is fairly straight forward than open-ended testing to measure efficiency and effectiveness. The above results have been discussed in detail. This study has finally concluded that to measure the usability of a system it is recommended to practice both the open-ended and task-based usability testing techniques.