Question: Luo, Hendriks, and Craik (2007) were interested in whether lists of words might be better remembered if they were paired with either pictures or sound effects. They asked participants to memorize lists of words under three different learning conditions. In the first condition, participants just saw a list of nouns that they were to remember (word-alone condition). In the second condition, the words were also accompanied by a picture of the object (picture condition). In the third condition, the words were also accompanied by a sound effect matching the object (sound effect condition). The researchers measured the proportion of words participants got correct in a later recognition test. Fictional data from four participants produce results similar to those of the original study. The average proportion of words recognized was M = 0.54 in the word-alone condition, M = 0.69 in the picture condition, and M = 0.838 in the sound effect condition. The source table below depicts the results of the ANOVA on the data from the four fictional participants.
a. Is it appropriate to perform post-hoc comparisons on the data? Why or why not?
b. Use the information provided in the ANOVA table to calculate R2. Interpret the effect size using Cohen's conventions. State what this R2 means in terms of the independent and dependent variables used in this study.