System Usability Scale for Measuring Usability of Social Network Applications from User Perspectives

Abstract

There are two common methods of the System Usability Scale (SUS) in quantitative usability evaluation, which are the Sauro & Lewis method and the Riihiaho method. The research aims to find the fittest SUS methods for usability evaluation of a social network application from those two methods. Using a comparative study approach, the research compared the number of valid scores of the 10 SUS indicators between those two methods. The valid score of each SUS indicator is obtained if the data of the SUS evaluation and the qualitative usability evaluation support each other. Qualitative data which was collected from five ordinary users for each SUS method by usability testing and interviews had been analyzed using a topdown analysis approach. The research obtained two main findings. Firstly, the Sauro & Lewis method is more relevant than the Riihiaho method from the comparison between the obtained SUS indicator scores and interview results. Secondly, the two methods have the same strength of relevance when the SUS indicator scores are compared with the usability testing result. Based on those findings, the Sauro & Lewis method may be fitter than the Riihiaho method for evaluating the usability of a social network application, from the user perspective.