Introduction to Volume 12, Issue 2, February 2017

We are delighted to publish an editorial by Dr. Philip Kortum titled “Has Human Factors and Usability Lost Its Mojo?” In his editorial Kortum argues that our work user experience and human factors has not lived up to its potential. He provides many examples spanning web design, software, automotive, and medical fields where we as a professional community have fallen short and still have more work to do. He wraps up by offering specific suggestions to improve our performance and make a greater impact on society.

The first article is by Bernard Rummel titled “Beyond Average: Weibull Analysis of Task Completion Times.” In this article the author introduces a novel application of the Weibull distribution model to usability test data. By doing so, a usability practitioner is able to estimate task completion times when knowing task completion rates, and vice versa. In addition, the author provides a link to a spreadsheet so you can see how well you can predict your own usability data using the Weibull distribution.

The second article is by Jim Lewis and Oğuzhan Erdinç titled “User Experience Rating Scales with 7, 11, or 101 Points: Does It Matter?” In their article, they compare Likert-style rating scales with a visual analog scale (VAS). This is important to any UX researcher who is considering the use of a continuous scale, as there are certain characteristics which differ from more traditional Likert-scale questions.