Abstract
Usability does not exist in any absolute sense; it can only be defined with reference to particular contexts. This, in turn, means that there are no absolute measures of usability, since, if the usability of an artifact is defined by the context in which that artifact is used, measures of usability must of necessity be defined by that context too. Despite this, there is a need for broad general measures which can be used to compare usability across a range of contexts. In addition, there is a need for ‘quick and dirty’ methods to allow low cost assessments of usability in industrial systems evaluation. This chapter describes the System Usability Scale (SUS) a reliable, low-cost usability scale that can be used for global assessments of systems usability.
The System Usability Scale (SUS) (PDF, 150 kb)
Does a PhD pay off financially? The author recently helped conduct the statistical analysis of the UPA 2009 salary survey, and used this opportunity to look into the data to see if he could calculate how much a PhD affects salaries in this profession. The data set contained salary information for a wide range of jobs in the profession—usability engineers, designers, managers and information architects.
How much a PhD is worth- the price of a PhD in the usability profession
Published in the ‘Ergonomics in Design’ journal in 1997. The author collected and created this list of 34 thumb rules (given below in order of priority) that were found particularly useful during the design process by colleagues working in the human-computer interface (HCI) design field.
- Know thy user, and YOU are not thy user.
- Things that look the same should act the same.
- Everyone makes mistakes, so every mistake should be fixable.
- The information for the decision needs to be there when the decision is needed.
- Error messages should actually mean something to the user, and tell the user how to fix the problem.
- Every action should have a reaction.
- Don’t overload the user’s buffers.
- Consistency, consistency, consistency.
- Minimize the need for a mighty memory.
- Keep it simple.
- The more you do something, the easier it should be to do.
- The user should always know what is happening.
- The user should control the system. The system shouldn’t control the user. The user is the boss, and the system should show it.
- The idea is to empower the user, not speed up the system.
- Eliminate unnecessary decisions, and illuminate the rest.
- If I made an error, let me know about it before I get into REAL trouble.
- The best journey is the one with the fewest steps. Shorten the distance between the user and their goal.
- The user should be able to do what the user wants to do.
- Things that look different should act different.
- You should always know how to find out what to do next.
- Don’t let people accidentally shoot themselves.
- Even experts are novices at some point. Provide help.
- Design for regular people and the real world.
- Keep it neat. Keep it organized.
- Provide a way to bail out and start over.
- The fault is not in thyself, but in thy system.
- If it is not needed, it’s not needed.
- Color is information.
- Everything in its place, and a place for everything.
- The user should be in a good mood when done.
- If I made an error, at least let me finish my thought before I have to fix it.
- Cute is not a good adjective for systems.
- Let people shape the system to themselves, and paint it with their own personality.
- To know the system is to love it.
Expert Ratings of Usability Maxims (article access requires purchase)
The author desribes A/B tests and multivariate tests (MVT), the difference between them and how one can choose which best fits their needs. A comparison between the techniques is mentioned, taking into consideration the overall use of the testing technique, coding needs, design needs, granularity of results and other considerations.
Landing Page Testing: Choosing Between A/B Or Multivariate Approaches
Heuristic evaluation (Nielsen and Molich, 1990; Nielsen 1994) is a usability engineering method for finding the usability problems in a user interface design so that they can be attended to as part of an iterative design process. Heuristic evaluation involves having a small set of evaluators examine the interface and judge its compliance with recognized usability principles (the “heuristics”).
In general, heuristic evaluation is difficult for a single individual to do because one person will never be able to find all the usability problems in an interface. Luckily, experience from many different projects has shown that different people find different usability problems. Therefore, it is possible to improve the effectiveness of the method significantly by involving multiple evaluators.
How to Conduct a Heuristic Evaluation
This study presents a cross-user usability test approach and analysis technique that extends beyond merely identifying the existence of a usability problem to introducing an empirical basis for identifying the type of usability problem that exists. For experimental purposes, 60 users were tested with three levels of user-competency determined by experience in using: (1) computers, and (2) the tested application. Applying the Tukey honestly significant difference (HSD) test to each test element provided statistical comparison between different experience levels.
Analysis results between experience levels suggested which levels encountered usability problems. The authors demonstrate that statistical calculations of cross-user data can render empirical support for categorizing usability problems.
Cross-user analysis: Benefits of skill level comparison in usability testing (300 kb)
In this document from 2004, then recent, relevant research about Web site design and older adult users are reviewed. From the research reviewed here, the authors developed a set of heuristics to use in persona-based, task-based reviews of 50 Web sites that older adult users are likely to go to.
Designing Web Sites for Older Adults: A Review of Recent, Relevant Research (PDF, 380 kb)
This document was published on December 14, 2004.
The International Journal of Mobile Human Computer Interaction (IJMHCI) brings together a comprehensive collection of research articles from international experts on the design, evaluation, and use of innovative handheld, mobile, and wearable technologies.
This journal will also consider issues associated with the social and/or organizational impacts of such technologies. Emerging theories, methods, and interaction designs are included and complemented with case studies, which demonstrate the practical application of these new ideas.
International Journal of Mobile Human Computer Interaction (IJMHCI)
In this document from 2005, findings from an expert review of 50 Web sites are presented. In a variation on the traditional heuristic evaluation methodology, heuristics were derived from research about older adults and Web design to perform persona-based, task-based reviews of Web sites that older adult users are likely to go to. The heuristics are extracted from our findings in Designing Web Sites for Older Adults: A Review of Recent, Relevant Research.
Designing web sites for older adults: Expert review of usability for older adults at 50 web sites (PDF, 1.7 mb)
Summary
As their usability approach matures, organizations typically progress through the same sequence of stages, from initial hostility to widespread reliance on user research. An organization that reaches the managed usability stage still has far to go to reach usability nirvana. Attaining these higher maturity levels requires many years of effort.
Stage 1: Hostility Toward Usability
Stage 2: Developer-Centered Usability
Stage 3: Skunkworks Usability
Stage 4: Dedicated Usability Budget
Stage 5: Managed Usability
Stage 6: Systematic Usability Process
Stage 7: Integrated User-Centered Design
Stage 8: User-Driven Corporation
Corporate Usability Maturity: Stages 1-4
Corporate Usability Maturity: Stages 5-8