Iterative Usability Testing as Continuous Feedback: A Control Systems Perspective

Peer-reviewed Article

pp. 18-27Download full article (PDF)

Abstract

This paper argues that in the field of usability, debates
about number of users, the use of statistics, etc. in the abstract are pointless
and even counter-productive. We propose that the answers depend on the research
questions and business objectives of each project and thus cannot be discussed
in absolute terms. Sometimes usability testing is done with an implicit
or explicit hypothesis in mind. At other times the purpose of testing is
to guide iterative design. These two approaches call for different study
designs and treatment of data. We apply control systems theory to the topic
of usability to highlight and frame the value of iterative usability testing
in the design lifecycle. Within this new metaphor, iterative testing is
a form of feedback which is most effective and resource-efficient if done
as often as practically possible with project resources and timelines in
mind.

Practitioner’s Take Away

  • Do not debate the appropriateness of specific user research methods
    in the abstract.
  • Before selecting a research method, always clarify the research questions
    and business objectives of each project and get team buy in.
  • Consider iterative usability testing a form of feedback on the progress
    towards specific design and business goals.
  • Start doing iterative testing as early as possible in the design lifecycle.
  • Conduct iterative testing as often as practically possible with project
    resources and timelines in mind.