Iconic memory is a type of memory that holds visual information for about half a second (0.5 seconds). To demonstrate this type of memory, participants were shown three rows of four letters for 50 milliseconds. They were then asked to recall as many letters as possible, with a 0-, 0.5-, or 1.0-second delay before responding. Researchers hypothesized that longer delays would result in poorer recall. The number of letters correctly recalled is given in the table.

Delay Before Recall

0 0.5 1

6 7 1

5 5 4

7 8 5

10 3 5

10 3 2

10 10 7

a) Complete theF-table. (Round your values forMSandFto two decimal places.)

Source of Variation SS df MS F

Between groups ___ ___ ____ ____

Within groups (error) ____ ___ _____

Total ____ ____

(b) Compute Tukey's HSD post hoc test and interpret the results. (Assume alpha equal to 0.05. Round your answer to two decimal places.)

The critical value is _______for each pairwise comparison.

(c) Which of the comparisons had significant differences? (Select all that apply.)

___ Recall following no delay was significantly different from recall following a one second delay.

___Recall following no delay was significantly different from recall following a half second delay.

___The null hypothesis of no difference should be retained because none of the pairwise comparisons demonstrate a significant difference.

___Recall following a half second delay was significantly different from recall following a one second delay.