Codein-A New Notation for GOMS to Handle Evaluations of Reality-Based Interaction Style Interfaces

Georgios Christou, Frank E. Ritter, Robert J K Jacob

Research output: Contribution to journalArticle

7 Scopus citations


We propose a new diagrammatic notation system for Goals, Operators, Methods, Selection rules (GOMS), called Codein, with extensions to support the evaluation of Reality Based Interaction Styles. The proposed notation gives added power to GOMS to model and evaluate the task completion time of parallel actions during the performance of a task, something that was previously only possible using CPM-GOMS, which is far more complicated to use. Codein's evaluative power is verified through an experiment. The first condition of the experiment compares the completion time predicted by a GOMSL model, a Codein model, and the actual completion time of participants in a direct manipulation task. The second compares the completion time of participants in a Tangible User Interface task with predictions by a GOMSL model and a Codein model. Predicted task times by Codein in both conditions come close to the actual experimental results.

Original languageEnglish (US)
Pages (from-to)189-201
Number of pages13
JournalInternational Journal of Human-Computer Interaction
Issue number3
StatePublished - Mar 1 2012


All Science Journal Classification (ASJC) codes

  • Human Factors and Ergonomics
  • Human-Computer Interaction
  • Computer Science Applications

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