Text size
  • Small
  • Medium
  • Large
Contrast
  • Standard
  • Blue text on blue
  • High contrast (Yellow text on black)
  • Blue text on beige

    Heterogeneity in the Usability Evaluation Process

    People and Computers XXII
    Culture, Creativity, Interaction

    Proceedings of HCI 2008
    The 22nd British HCI Group Annual Conference
    Liverpool John Moores University, UK

    1 - 5 September 2008

    AUTHORS

    Martin Schmettow

    ABSTRACT

    Current prediction models for usability evaluations are based on stochastic distributions derived from series of Bernoulli processes. The underlying assumption of these models is a homogeneous detection probability despite of it being intuitively unrealistic. This paper contributes a simple statistical test for existence of heterogeneity in the process. The compound beta-binomial model is proposed to incorporate sources of heterogeneity and compared to the binomial model. Analysis of several data sets from the literature illustrates the methods and reveals that heterogeneity occurs in most situations. Finally, it is demonstrated how heterogeneity biases the prediction of evaluation processes. Open research questions are discussed and preliminary advice for practitioners for controlling their processes is given.

    PAPER FORMATS

    PDF filePDF Version of this Paper (595kb)

    HCI 2008: People and Computers XXII Culture, Creativity, Interaction (cover)

    Print copies of People and Computers XXII Culture, Creativity, Interaction (Vol. 1)
    ISBN 978-1-906124-04-5
    RRP £85

    Available from the BCS bookshop

    People and Computers XXII Culture, Creativity, Interaction (Vol. 2)
    ISBN 978-1-906124-06-9
    RRP £85

    Available from the BCS bookshop