INTRODUCTIONWith the increasing emphasis on product user experience in recent days, it is essential to discuss the reliability of usability evaluation methods. usability. Usability assessment methods are primarily used to identify issues and assign severity to them, which will help development teams resolve usability issues by priority. As we can see, the usability of the final product depends a lot on the results of a usability evaluation and there has been debate about the reliability of the evaluation methods we have been using for a long time. In this article, I will mainly discuss the reliability of the most commonly used evaluation methods (expert review, usability testing) and also discuss the impact of evaluator experience on the evaluation of the usability. Ultimately, this article will include takeaways for the practitioner to follow in order to create increased reliability in the usability evaluation method followed. practitioners. In an ideal scenario, we would expect the results of usability evaluation methods to be independent of the practitioners using them and the product being evaluated (Hartson, Andre, & Williges, 2001). But various studies have been performed to show that results varied widely, and there has been no consensus among practitioners on major issues such as: how many participants to choose for usability evaluation, when use heuristic evaluation, when to use expert opinions, etc. New entrants to the industry tend to rely on the results of previous research conducted in these areas. Such use of prior experimental research...... middle of paper ......ress. doi:10.1145/634126.634127 Lindgaard, G. (2007). Usability testing: what have we overlooked? Information Systems, 1415-1424.Molich, R., Ede, M., Kaasgaard, K., and Karyukin, B. (2004). Comparative usability assessment. Behavior and Information Technology, 23(1), 65-74. doi:10.1080/0144929032000173951Nielsen, J. (1992). Finding usability problems through heuristic evaluation. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems CHI 92, 3(7), 373-380. ACM Press. doi:10.1145/142750.142834Virzi, R.A. (1992). Refine the testing phase of usability evaluation: How many topics are enough? Human Factors, 34(4), 457-468. Wharton, C, Rieman, J., Lewis, C., & Polson, P. (1994). The cognitive method step by step: a practitioner's guide. (J Nielsen & RL Mack, Eds.) Usability Inspection Methods. John Wiley and Sons. do I:10.1108/09685220910944731