Conditional co-occurrence probability acts like frequency in predicting fixation durations

  • James K. Y. Ong Upper Austria University of Applied Sciences
  • Reinhold Kliegl University of Potsdam
Keywords: co-occurrence probability, Cloze predictability, eye movement, frequency, fixation duration


The predictability of an upcoming word has been found to be a useful predictor in eye movement research, but is expensive to collect and subjective in nature. It would be desirable to have other predictors that are easier to collect and objective in nature if these predictors were capable of capturing the information stored in predictability. This paper contributes to this discussion by testing a possible predictor: conditional co-occurrence probability. This measure is a simple statistical representation of the relatedness of the current word to its context, based only on word co-occurrence patterns in data taken from the Internet. In the regression analyses, conditional co-occurrence probability acts like lexical frequency in predicting fixation durations, and its addition does not greatly improve the model fits. We conclude that readers do not seem to use the information contained within conditional co-occurrence probability during reading for meaning, and that similar simple measures of semantic relatedness are unlikely to be able to replace predictability as a predictor for fixation durations. Keywords: Co-occurrence probability, Cloze predictability, frequency, eye movement, fixation duration.
How to Cite
Ong, J. K. Y., & Kliegl, R. (2008). Conditional co-occurrence probability acts like frequency in predicting fixation durations. Journal of Eye Movement Research, 2(1).