I am having some trouble confirming that I am on the right track and I hope someone can help me out.
I have a data set with 9 products each of which has received 8 treatments, including the control this makes a 9 Product x 9 Treatment matrix that was organised in a reduced Latin square.
Participants in the experiment were required to provide user ratings for each of the 9 products, one each with a different treatment applied. Consequently each participant seen each product once and each treatment once. This means that every participant contributed to each of the mean user ratings below.
I then worked out the mean user ratings for the control and each of the user ratings. Below is an example:
Control T1 T2 T3 T4 T5 T6 T7 T8 Mean Ratings 4.74 -1.77 -1.88 7.77 4.08 6.90 13.66 17.13 19.44
I want to find out the level of effect of each treatment in standard deviations from the mean of the control, which received no treatment.
- The mean user ratings for the control and each of the treatments were taken from the same population and are selected at random
- My mean user ratings range from -100 to +100
- My data is normally or approximately normally distributed.
- The sample size for each mean user ratings is > 30
- The Standard Deviation is known.
Question: Is it possible using Z-tests to compare the the mean user rating of each of the treatments to the mean of the control? Is this the correct test?
So the comparisons will be in the from of
Control V T1 then
Control V T2 etc.
I did ask a similar question previously, but that focused on my efforts and what I have attempted so far. I wanted to ask this question separately to make sure I was on the right track before I keep going.
This has been driving me slightly crazy for a few days not so any help would be seriously appreciated, thanks.