Frequency of Occurrence as a Factor in Interference on the Stroop Word-Color Test

Abstract

In 1735, J. R. Stroop developed a test to study the interference that the written word of a color has on the naming of the color in which the word is printed. This test was unique in that the source of interference was in the materials. The difference in time for reading words printed in colors and the same words printed in blad; is the measure of the interference of color stimuli on reading words. The difference in time for naming colors in which the words are printed and the same color printed in squares is the measure of interference of conflicting word stimuli on naming colors. The main portion of this test concerns the interference char the conflicting word stimuli has upon the time for naming 60 colors. Ss must attend to the color of ink while ignoring the printed word. Stroop concluded that the interference was a result of one's greater experience with words in which the proper response is reading the word, while color may call forth many different responses. This report will study the relevance of frequency count of the words used to the observed interference in the Stroop Word-Color Test. Stroop's test has three segments to be read aloud. The first part contains a sheet of GO words printed in black naming five colors. The second part has a sheet of 60 squares of the five colors. The third and most crucial part is a sheet of 60 words printed in a color different from the one named. Ss had to name, as rapidly as possible, the color of the ink in which the word was printed. A group of GO Ss read aloud through the three sheets. A stop watch was used to record the time taken by each S to complete each sheet. After Ss had finished the Stroop test they were given a modified test in which the words signifying the colors in the sheet were replaced by words having a similar meaning but a less common usage. With the aid of the Kucera-Francis (1967) frequency count for the English language all substimte words were less frequently used than the words in the Stroop test. For example, aqua was substituted for blue in an attempt to maintain some meaning but decrease frequency. Ss were 60 students in undergraduate psychology classes at a state university. To avoid progressive errors biasing the results, the order of presentation of the Stroop test and the modified test was completely randomized. Since a repeated-treatments design was used, two sets of figures were obtained for each individual. On the Stroop WordColor Test the M time was 67 sec.; with the modified test M = 44 sec. The modified test was completed in significantly less time than the Stroop Word-Color Test (t = 10.95, p < ,001).