A developmental psychologist is examining the development of language skills from age 2 to age 4. Three different groups of children are obtained, one for each age, with n = 18 children in each group. Each child is given a language-skills assessment test. The resulting data were analyzed with an ANOVA to test for mean differences between age groups. The results of the ANOVA are presented in the following table. Fill in all of missing values:
Source: SS df MS F
Between: 48 -
Within:
– – –
Total 252 - -
Find the critical F-value using an α = .01.
What can you conclude with respect to the null hypothesis?
Calculate η2 and state whether the effect is small, medium, or large.