Researchers at the University of Virginia randomly assigned 60 four-year-olds to one of three tasks: watch a fast-paced television cartoon, watch a slower-paced educational cartoon, or participate in a drawing activity for a nine-minute period. At the end of the period, the researchers tested the children's "executive function," using various tests intended to measure characteristics such as self-regulation and working memory. These researchers found that those children who watched the fast-paced cartoon scored lower on the different measures of executive function than those children who either watched the educational cartoon or did the drawing activity. [Source: Lillard, A. S. & Peterson, J. (2011). The immediate impact of different types of television on young children's executive function. Pediatrics, 128(4), 644-649.]
Suppose you are a cognitive psychologist and want to see whether you would find similar results using a repeated-measures design and focusing on a measure of attention. You collect a random sample of 30 four-year-olds to each participate in all three activities, measuring their attention after each activity. To avoid order and carryover effects, you randomize the order in which each child participates in the activity and space the three activities at least one week apart.
You use a statistical computing package, such as SPSS, to conduct a repeated-measures ANOVA. Assume your data satisfies the required assumptions for a repeated-measures ANOVA.
Descriptive Statistics
Mean
Std Deviation
N
Fast-Paced Cartoon
29.5213
10.3085
30
Educational Cartoon
33.0213
10.1650
30
Drawing Activity
33.5480
10.3153
30
Tests of Within-Subjects Effects
Type III Sum of Squares
df
Mean Square
F
Sig
Activity Type
Sphericity Assumed
287.414
2
143.707
36.265
0.000
Greenhouse-Geisser
287.414
1.880
152.880
36.265
0.000
Huynh-Feldt
287.414
1.940
148.152
36.265
0.000
Lower-Bound
287.414
1
287.414
36.265
0.000
Error (Activity Type)
Sphericity Assumed
229.839
58
3.963
Greenhouse-Geisser
229.839
54.520
4.216
Huynh-Feldt
229.839
56.260
4.085
Lower-Bound
229.839
29
7.925
The two prior tables consist of the output of the statistical computing package. Considering these results, fill in the blanks in the following statement that describes the results in APA format. Assume that your chosen significance level is α = .05. (Note: These results are hypothetical.)
The means and standard deviations are presented in Table 1. A repeated-measures analysis of variance indicated that there were significant differences among the attention scores after four-year-old children watch a fast-paced cartoon, watch an educational cartoon, or participate in a drawing activity, F(df1, df2) = F-value, p = p-value, η² = effect size.
TABLE 1
Attention scores of four-year-olds after nine minutes of a fast-paced cartoon, an educational cartoon, or a drawing activity
Fast-Paced Cartoon
Educational Cartoon
Drawing Activity
M
SD