Off-campus UMass Amherst users: To download campus access theses, please use the following link to log into our proxy server with your UMass Amherst user name and password.

Non-UMass Amherst users: Please talk to your librarian about requesting this thesis through interlibrary loan.

Theses that have an embargo placed on them will not be available to anyone until the embargo expires.

Access Type

Campus Access

Document Type

thesis

Degree Program

Psychology

Degree Type

Master of Science (M.S.)

Year Degree Awarded

2012

Month Degree Awarded

May

Keywords

distribution, fixation durations, frequency, predictability, reading

Abstract

The most important predictors of fixation durations in reading are a word’s frequency of occurrence (as measured by counts in large corpora) and its predictability in context (as measured by cloze probability). Two recent eye-tracking studies investigated distributional effects of word frequency (Staub et al, 2010) and word predictability (Staub, 2011) separately. The present study investigates the distributions associated with these two variables when they are manipulated in the same experiment. When considering the overall means, frequency and predictability showed significant main effects (LF>HF; LP>HP), with no interaction. In addition, we found evidence supporting the previous distributional findings where frequency and predictability affect all fixations (causing a shift in the distribution), but frequency also has a special influence on the longest fixations. Interestingly, the model fits suggested that there was an interaction between the predictors in first fixation duration. However, this effect was not visible in the vincentiles (which are plots of the actual data) and it appeared to be conditional on four particular subjects. Since we did not find convincing evidence of an interaction in our distributional analysis, the present findings provide support for theories of fixation durations whereby frequency and predictability combine additively.

DOI

https://doi.org/10.7275/2759783

First Advisor

Adrian Staub

COinS