What is a usability problem? A usability problem can be defined as a problem that delays or prevents a user from performing a certain task on a product (software, hardware, website) and forces the user to turn to other resources (people, manuals, help) to perform the task. A usability issue can potentially cause a user to reject the product and look for alternatives. Finding and solving a usability problem is the goal of all usability efforts undertaken by a product development organization. There are numerous methods for evaluating the usability of a product, but all methods focus on problem detection and don't go far enough to handle categorization and prioritization. An important part of usability costs is associated not with research but with troubleshooting, so the categorization and assignment of severity levels to usability problems should be robust, reliable and should justify the cost associated with fixing usability problems (Hertzum, 2006). Categorization and prioritization are traditionally of no scientific interest and have mainly been studied in the context of comparing evaluation methods (Hesserehl, 2000). This article will focus on the existing literature for categorizing usability problems, present a critical analysis of the methods and also highlight their areas of positive influence. The article will then present a professional's point of view on the categorization and lead to a conclusion. Existing literature on usability problem categorization This section of the article reviews some existing approaches to usability problem categorization. Detailed scales and ranges for each of the approaches discussed below are provided in the Appendix for your reference. Rubin and Chisnell modelRubin and Chisnell (...... middle of paper ...... ign. INTERNATIONAL JOURNAL OF HUMAN–COMPUTER INTERACTION, 21(2), 125–146. Keenan, SL, Hartson, H.R., Kafura, D.G. and Schulma, R.S. (1999).The taxonomy of the usability problem: a framework for the classification and empirical analysis of software, 4(1), 71–104.Molich, R., Jeffries, R . and Dumas, J.S. (2007) Making usability recommendations useful and usable Journal of Usability Studies, 2(4), 162–179. Severity Ratings for Usability Problems: Article by Jakob Nielsen Retrieved February 7, 2014, from http://www.nngroup.com/articles/how-to-rate-the-severity-of-usability-problems/Nielsen, J. (2006) Severity ratings for usability problems. Useit.com, 4–5.Rubin, J., & Chisnell, D. (2008) Handbook of usability testing (2nd ed.). C. (1999). Usability interface: gravity scales. Usability interface, 5(4).