An investigator tested the relationship between the supposed

An investigator tested the relationship between the supposed difficulty of a task and task performance. Twenty- four participants worked on the identical spatial ability task, but six of these individuals were led to believe that the task was of low difficulty, six were led to believe that the task was of moderate difficulty, six were led to believe that the task was of high difficulty, and six were not given any information about the task’s difficulty. Scores could range from 0 to 10, with higher values indicating better task performance. The data follow:

Low Moderate High No Information

8 6 4 4

7 7 1 5

5 4 2 5

8 5 4 6

9 4 6 8

7 6 3 6

Test for a relationship between the supposed task difficulty and task performance using a one- way analysis of variance.

Solution

H0: all 3 means are equal

Ha: atleast 2 are not equal

As p is less than 0.05 reject null hypothesis.