The System Usability Scale (SUS) has been used in industrial user experience research since the mid-1980s. Despite its age, the SUS is still a popular measure, widely used in benchmark tests of software products to measure perceived usability. One reason for its popularity is the extent to which its measurement properties have been comprehensively studied
When learning statistics, you’ll encounter many formulas based on principles of probability and mathematics. But statistics isn’t just a formulaic process where you enter data and are told what to do. Statistics should guide, not dictate, decisions. In making decisions, though, there are different styles of interpreting data. Although a lot of people think statistics
Surveys are one of the most popular methods in applied research. While many have argued that surveys are overused, it’s hard to believe that surveys have no place in multi-method UX research. When conducting survey-based research, you’ll often encounter the terms census, poll, and questionnaire used in conjunction with—and often interchangeably with—the term survey. But
In a previous article, we described three ways to estimate SUS scores from UX-Lite™ (and UMUX-Lite) scores, using either both items (perceived measures of Ease and Usefulness) or the Ease item only: Two-item interpolation: Scaling the mean of both items to a 100-point scale (Lite). One-item interpolation: Scaling just the Ease item to a 100-point
If you know even just a little about statistics, you know that the value .05 is special. When the p-value obtained from conducting a statistical test falls below .05, it typically gets a special designation we call statistically significant. This is the conventional threshold for publishing findings in academic journals, and consequently, it is ascribed
For the past few years, we’ve written extensively about our research and usage of the UMUX-Lite. That research has followed the increase in popularity of this compact questionnaire. From its initial publication in 2013, the UMUX-Lite (Usability Metric for User Experience—Lite Version) has become an increasingly popular measure of perceived usability. Figure 1 shows the
The UMUX-Lite is a popular two-item measure of perceived usability that combines perceived ratings of Ease and Usefulness, as shown in Figure 1. Figure 1: Standard version of the UMUX-Lite (standard item wording with five-point scales). Since we began regularly using the UMUX-Lite in our practice, we’ve had numerous clients ask whether it
The original wording of the UMUX-Lite Perceived Usefulness item is “{Product}’s capabilities meet my requirements.” Since we started using the UMUX-Lite in our practice, we’ve had numerous clients ask whether it would be possible to simplify the wording of this item to more closely match the simplicity of the UMUX-Lite Perceived Ease item, “{Product} is
Sample size estimation is a critical step in research planning, including when you’re trying to detect differences in measures like Net Promoter Scores. Too small of a sample and you risk not being able to differentiate real differences from sampling error. Too large of a sample and you risk wasting resources—researchers’ and respondents’ time and,
Hypothesis testing is one of the most common frameworks for making decisions with data in both scientific and industrial contexts. But this statistical framework, formally called Null Hypothesis Statistics Testing (NHST), can be confusing (and controversial). In an earlier article, we showed how to use the core framework of statistical hypothesis testing: you start with
