Estimating Productivity: Composite Operators for Keystroke Level Modeling

  • Jeff Sauro
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5610)


Task time is a measure of productivity in an interface. Keystroke Level Modeling (KLM) can predict experienced user task time to within 10 to 30% of actual times. One of the biggest constraints to implementing KLM is the tedious aspect of estimating the low-level motor and cognitive actions of the users. The method proposed here combines common actions in applications into high-level operators (composite operators) that represent the average error-free time (e.g. to click on a button, select from a drop-down, type into a text-box). The combined operators dramatically reduce the amount of time and error in building an estimate of productivity. An empirical test of 26 users across two enterprise web-applications found this method to estimate the mean observed time to within 10%. The composite operators lend themselves to use by designers and product developers early in development without the need for different prototyping environments or tedious calculations.


Task Time Cognitive Modeling Estimate Productivity Composite Operator Task Completion Time 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Jeff Sauro
    • 1
  1. 1.Oracle, 1 Technology WayDenverUSA

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