Question

In an effort to promote a new product, a marketing firm asks participants to rate the effectiveness of ads that varied by length (short, long) and by type of technology (static, dynamic, interactive). Higher ratings indicated greater effectiveness.

Source of Variation	SS	df	MS	F
Length	15
Technology
Length × Technology	142
Error	570	114
Total	807

(a) Complete the F-table and make a decision to retain or reject the null hypothesis for each hypothesis test. (Assume experimentwise alpha equal to 0.05.)

Source of Variation	SS	df	MS	F
Length	15
Technology
Length × Technology	142
Error	570	114
Total	807

State the decision for the main effect of length.

Retain the null hypothesis. or Reject the null hypothesis.    

State the decision for the main effect of technology.

Retain the null hypothesis.or Reject the null hypothesis.    

State the decision for the interaction effect.

Retain the null hypothesis.or Reject the null hypothesis.    

(b) Based on the results you obtained, what is the next step?

A)Compute simple main effect tests for the significant interaction.

B)No further analysis is needed because none of the effects are significant.  

C) Compute pairwise comparisons for the length factor.

D)Compute pairwise comparisons for the technology factor.

Answer 1

Source of Variation	SS	df	MS	F	F crit
Length	15	1	15	3	3.92
Technology	80	2	40	8	3.08
Length × Technology	142	2	71	14.2	3.08
Error	570	114	5
Total	807	119

decision for the main effect of length.: Retain the null hypothesis

decision for the main effect of technology: Reject the null hypothesis.   

decision for the interaction effect.:Reject the null hypothesis.   

b)D)Compute pairwise comparisons for the technology factor.