Question

Scientist warn that food shortages are an impending future issue for humans. A potential solution is eating non-traditional foods in the western world. An experimental psychologist knows that westerners are uncomfortable eating food other cultures have no trouble eating. The psychologist developed a method to help individuals tolerate more the eating of non-ordinary food. However, the psychologist is unsure which type(s) of foods the method will be more effective on. The psychologist has some participants go through the method and then asks them to eat each of the following out of the ordinary foods: stick insects, bovine testicles, fish eyes, and Witchetty grubs. On each occasion, participants are measured on how many seconds it takes before they gagged while eating the food. The data are in the table below. What can the psychologist concluded with α = 0.01?

stick	bovine	fish	grub
7 8 6 4 8 7 9 11	6 4 1 2 3 4 1 5	1 2 3 1 4 4 1 7	5 4 7 8 7 6 1 0

a) What is the appropriate test statistic?
---Select--- na one-way ANOVA within-subjects ANOVA two-way ANOVA

b) Compute the appropriate test statistic(s) to make a decision about H₀.
p-value =  ; Decision:  ---Select--- Reject H0 Fail to reject H0

c) Using the SPSS results, compute the corresponding effect size(s) and indicate magnitude(s).
η² =  ;  ---Select--- na trivial effect small effect medium effect large effect

d) Make an interpretation based on the results.

At least one of the foods differed on time before gagging.None of the foods differed on time before gagging.    

Answer 1

A)The appropriate test statistic is one way ANOVA

Sum of Squares df Mean Square Sig Between Groups 105.844 35.281 6.866 .001 Within Groups 143.875 28 5.138 Total 249.719 31

B)Critical value : F_(3,28,.01)= 4.57

Test Statistic : F= 6.866

Decision : Reject H₀

C)Effect size

= 105.844/249.719 = 0.4238

SS/SST

Magnitude : Medium effect

D)The interpretation is atleast one of the foods differed on time before gagging