Write limitation that prevent from concluding visual imagery

Question

1. A group of 30 participants is divided in half based on their self-rating of the vividness of their visual imagery. Each participant is tested on how many colors of objects he or she can correctly recall from a briefly seen display. The results of this experiment are below. (Note: You will need one column in SPSS for the IV with two levels [vivid/less vivid] and one for the DV.)

Vivid	Less Vivid
18	14
17	12
16	13
15	10
14	8
13	8
9	7
8	6
7	5
6	4
5	3
11	2
13	5
18	11
18	14

Enter the data into SPSS and perform an independent samples t-test of the null hypothesis that vividness of visual imagery does not affect the recall of colors; use alpha = .01 (or 99% confidence), two-tailed. (Hint: The default alpha level is not .01; see options in the test menu.) What is your statistical conclusion?

1. SPSS output

2. Results write-up

3. What are some of the limitations that prevent you from concluding that the visual imagery causes improved color recall in this type of experiment?