How to specify the participant group size for usability studies: a practitioner's guide

Using secondary literature, this article helps practitioners to specify the participant group size for a usability study. It is also designed to help practitioners understand and articulate the basis, risks, and implications associated with any specification. It is designed to be accessible to the typical practitioner and covers those study scenarios that are common in commercial contexts.

[1]  Jakob Nielsen,et al.  Determining Usability Test Sample Size , 2006 .

[2]  L. Faulkner.  Beyond the five-user assumption: Benefits of increased sample sizes in usability testing , 2003, Behavior research methods, instruments, & computers : a journal of the Psychonomic Society, Inc.

[3]  Ritchie Macefield.  Conceptual Models and Usability , 2006 .

[4]  Jakob Nielsen,et al.  A mathematical model of the finding of usability problems , 1993, INTERCHI.

[5]  William Hudson.  How many users does it take to change a Web site? , 2001, CHIB.

[6]  M. Angela Sasse,et al.  Eliciting and describing users' models of computer systems , 1997 .

[7]  Jean Scholtz,et al.  Common industry format for usability test reports , 2000, CHI Extended Abstracts.

[8]  Debora Shaw,et al.  Handbook of usability testing: How to plan, design, and conduct effective tests , 1996 .

[9]  Bengt Klefsjö,et al.  The Six Sigma Handbook , 2002 .

[10]  Thomas Pyzdek,et al.  The Six Sigma Handbook , 2000 .

[11]  Yvonne Rogers,et al.  Models in the mind : theory, perspective and application , 1992 .

[12]  M. Furlong,et al.  Eight Was Not Enough , 2009 .

[13]  C. Dolan,et al.  Statistical power , 2007 .

[14]  Robert A. Virzi,et al.  Refining the Test Phase of Usability Evaluation: How Many Subjects Is Enough? , 1992 .

[15]  Jef Raskin,et al.  Viewpoint: Intuitive equals familiar , 1994, CACM.

[16]  John McKean.  Information Masters: Secrets of the Customer Race , 1999 .

[17]  Gilbert Cockton,et al.  Why and when five test users aren’t enough , 2001 .

[18]  Jared M. Spool,et al.  Testing web sites: five users is nowhere near enough , 2001, CHI Extended Abstracts.

[19]  Jef Raskin.  Intuitive equals familiar , 1994 .