This article appeared first at Learnability Matters, a blog by Kern Communications. It was orignially written by Sneha Nair, and edited by yours truly. And, I have taken permission to shamelessly copy :)
Sometimes we want to do the right thing to increase our application’s usability but don’t know how and where to begin, what method is appropriate to maximize an optimal outcome.
We’ve heard of many methods from usability testing, focus group, expert review to contextual enquiry but what’s the difference and when do we use it? Contrasted below are two usability evaluation methods that are often used.
Expert Usability Review
|Who conducts them? |
Usability testing involves getting people from the target audience to evaluate your application while performing specific tasks. Usability experts watch the participants performing the tasks and analyse.
Kern provides usability testing services in India. Kern helps companies around the world understand Indian users and their usage patterns.
|An expert usability review is performed by usability experts. The usability experts inspect an application to identify potential usability problems. The experts review the applications based on published research, experience in watching user behavior in the usability lab and design heuristics. |
Kern follows a unique methodology for expert evaluations that gives a rigour and actionable results to clients. This methodology is a mixture of Heuristic Evaluation, GOMS, and Cognitive Walkthrough.
|How many users do I need? |
Usually 5-15 respondents are enough to find key usability issues in a usability test.
Kern helps clients understand how many users may be optimally needed for a test. Kern will also help clients understand where it would be ideal to conduct such a test.
Using Kern’s unique evaluation methodology, one expert evaluator can perform the evaluation without missing problems.
|How much would it cost me? |
Usability testing requires more time to plan and organize. Preparation of testing protocol, hiring a usability lab, recruiting and incentivising people from a target user group and conducting tests and analysis is time consuming and expensive. Usability testing is the most expensive usability evaluation method.
|An expert usability review is much cheaper when compared to usability testing. It’ll only take a few days to evaluate an application and write a report. You neither need to hire expensive labs nor recruit users; costs are significantly lower. |
With Kern’s unique methodology, we reduce the time taken for an expert usability evaluation, therefore saves you significant costs.
|How long does it take? |
Usability testing method involves detailed protocol scripting, participant recruiting, and conducting the test one by one, followed by data analysis and report generation, it is a time consuming process.
For a 15-20 people usability test, it usually takes 4-6 weeks, however Kern requires 3 weeks time – start to finish.
|Skilled evaluators can produce high-quality results in a limited time. At Kern, it usually takes about one to three weeks for an expert usability evaluation including a report of findings and recommendations. The time depends upon the complexity of the application/website.|
|What does it help me find? |
Usability testing is better at finding issues related to special domain knowledge of users and their task flows – what path do they follow while performing a task. If the usability testing protocol is designed well and covers key user tasks, user testing helps you find major usability problems.
With Kern’s unique methodology, evaluators find all key and many strategic and tactical usability issues. This helps clients’ schedule implementation.
|What are the disadvantages of usability testing and expert evaluation? |
Kern guarantees its clients accuracy of usability testing protocol and identification & recruitment of right users.
With Kern’s unique methodology, false positives are significantly reduced. Unlike other firms, Kern always uses experienced evaluators to perform evolutions.
|What are the advantages of usability testing and expert usability review? || |
|When do I use usability testing and when do I use an expert usability review?Usability testing is recommended for use later in the development process, when the extra value of finding the problems real users may encounter justifies its cost and time.
Kern recommends summative usability testing only: ||People often use expert usability reviews early on to straighten up their design in preparation for usability testing. Kern not only helps evaluate the application but also helps them give design directions.|
http://www.useit.com/papers/heuristic/ http://www.usabilitynews.com/news/article3616.asp http://www.userfocus.co.uk/articles/expertreviews.html http://www.oclc.org/policies/usability/testing/default.htm http://kmvirtual.com/2008/05/26/heuristic-evaluation-and-user-testing/ http://www.teced.com/PDFs/sigdoc97.pdf