Corroborating biased indicators: global and local agreement among objective and subjective estimates of printed word...

The internal validity of several types of experiments in experimental psychology and neuroscience depends in part on the possibility of controlling or manipulating critical lexical variables such as word frequency of occurrence. Two ways of estimating this variable are (1) objective frequency counts and (2) subjective ratings of word frequency. Each method produces estimates that generally agree (i.e., they are highly correlated) but that disagree substantially concerning the relative frequency of a number of words. To investigate this issue more closely, the global and local agreement of subjective frequency estimates was examined in detail for a pool of 6,202 words drawn from the OMNILEX database of French words (Desrochers, 2006; www.omnilex.uottawa.ca). The results indicated that objective and subjective frequencies are strongly correlated, subjective frequencies share a significant amount of bias variance with other lexical characteristics (e.g., imageability), and the codeterminants of subjective frequency are in an antagonistic relationship with one another. The implications of these results for the selection of lexical stimuli are discussed, and multiple variables to aid in item selection are reported. Supplemental materials for this study may be downloaded from brm.psychonomic-journals.org/content/supplemental.