For this alternate assignment I am providing you with an Excel spreadsheet that
ID: 3361063 • Letter: F
Question
For this alternate assignment I am providing you with an Excel spreadsheet that already contains all of the calculations for a 2-factor repeated measures design. Participants were asked to read information as it scrolled across a screen. They were then asked to recall as much of the information as possible.
The first factor is content difficulty and it has 2 levels (Easy vs. Difficult)
The second factor is the speed at which the information scrolled across the screen and it has 3 levels (Fast, Moderate, and Slow).
The Dependent Variable is the accuracy of their recall on a scale of 0 to 10
One tab is labeled “Small_within” and the other is labeled “Large_within”. These represent two hypothetical experimental results. Spend some time clicking back and forth between the two, and identify where there are similarities and differences in the two files.
Your assignment is to 1) explain what the two data sets share in common, and 2) what is different about the files, and 3) what this means for the final hypothesis testing.
Explanation / Answer
solution (1). The similarity between the two datasets is that though each observations are different, their cell means across each factor is the same. Moreover, the overall sum of the observations is also comparable. This implies that in small within dataset, the observations are so distributed that their within factor variance has a smaller contribution to the total variation.While, in large-within dataset, the proportion of total variance is largely dominated by the error variance.
solution(2). The difference corresponds to the within factor variance from the two datasets. the small-within dataset has a smaller contribution from error/within variance and thus, there is a significant difference between elements of both speed and ease factor. This is depicted in the lower p-values (<0.05) for both speed & ease factor effects test of difference in means.
Moreover, in the large-within dataset, the error variance is quite high as proportion of total variance which undermines the effects of ease & speed as factors causing differences. This is reflected in the high p-values (>0.05).
sol (3). The overall hypothesis test is rejected in the small-within dataset & it can be concluded that for both speed and ease, atleast one-pair is different. However, for the large-within dataset, there is insufficient evidence for the hypothesis of difference in group means across the two factors to be rejected.
The above interpretation comes from <0.05 p-values for the former while >0.05 p-values for the latter dataset.