QUESTION 15

Based on previous research and sound theoretical considerations an experimental psychologist believes that memory of pictures is superior to memory for words. To test this hypothesis the psychologist performs an experiment in which students from an introductory psychology class are used as subjects. Seven randomly selected students view 30 slides with random nouns printed on them andanothergroup of seven randomly selected students views 30 slides with actual pictures of the objects represented by the same nouns. Each slide contains either one picture or one noun and each slide is viewed for four seconds. After viewing all the slides subjects are given a recall test one hour later and the experimenter records the number of correctly remembered items. Use an alpha level of 0.05_{1 Tail}. The data are given in the table below:

# of pictures recalled	# of nouns recalled
18	12
21	9
22	21
25	17
23	16
19	10
28	15

What is SS₂?