In an effort to promote a new product, a marketing firm asksparticipants 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 | 10 | | | |
| Technology | | | | |
| Length ×Technology | 146 | | | |
| Error | 570 | 114 | | |
| Total | 856 | | | |
(a) Complete the F-table and make a decision to retainor reject the null hypothesis for each hypothesis test. (Assumeexperimentwise alpha equal to 0.05.)
Source of
Variation | SS | df | MS | F |
|---|
| Length | 10 | | | |
| Technology | | | | |
Length×
Technology | 146 | | | |
| Error | 570 | 114 | | |
| Total | 856 | | | |
State the decision for the main effect of length.
Retain the null hypothesis.
Reject the null hypothesis.   Â
State the decision for the main effect of technology.
Retain the null hypothesis.
Reject the null hypothesis.   Â
State the decision for the interaction effect.
Retain the null hypothesis.Reject the nullhypothesis.   Â
(b) Based on the results you obtained, what is the next step?
Compute simple main effect tests for the significantinteraction.
Compute pairwise comparisons for the technologyfactor.    Â
Compute pairwise comparisons for the length factor.
No further analysis is needed, because none of the effects aresignificant.
