I really suck at this so hope you could help me
ve a group of people attending a training course, in order to measure whether the training course is effective in improving attendees' knowledge. We did the following:
attendees will complete a pre-test (TRUE or FALSE only) before the training
attendees attending the training
attendees will complete a post-test (TRUE or FALSE only) after training
Both pre and post tests are having exactly the same questions, However the test is NOT tagged with barcode so i have NO way to know if a certain pre and post questionnaire belong to the same individual
Each paper has been scored out of 20 ,, and the scores i have entered in SPSS for every student for both the pre and post questionnaire
So for this can i just use the paired t test and will the interpretation still be valid or is there an alternative i can use to find the significance of the intervention and whether it was effective or not? or should i do the t-test to the sum of the scores for pre and post?
Thanks alot
Best Answer
How would you go about pairing them? A paired t-test asks whether the mean difference between paired observations is different from zero. For example, you might weigh people, put them on a diet, and then weigh them again some time later. An unpaired t-test would ask whether the average weight of the "before" group differs from the average weight of the "after" group. A paired t-test, however, compares each person's weight loss/gain.
It doesn't sound like you have any sensible way of pairing your questionnaires, so you cannot use a paired t-test. This isn't necessarily the end of the world--you can use an unpaired t-test instead: this would tell you whether there was a significant different in the two total scores.