You must use either planned or post hoc contrasts to determine which groups are different if you find a statistically significant ANCOVA. What determines whether you use planned or post hoc contrasts?
A) Whether the hypothesis is one-tailed (directional) or two-tailed (no direction)
B) Whether the data is normally distributed
C) The sample size
D) Whether the assumption of homogeneity of variance has been met or not

Question

Quizplus · Accepted Answer

Planned contrasts are used when specific hypotheses about group differences were made before the data was collected, while post hoc contrasts are used to explore differences between groups when no specific hypotheses were made in advance. The choice between planned or post hoc contrasts is determined by whether the research hypotheses were directional (one-tailed) or non-directional (two-tailed), not by the distribution of data, sample size, or homogeneity of variance assumptions.

You Must Use Either Planned or Post Hoc Contrasts to Determine