I need to conduct a sample size analysis for an experiment with the following characteristics:
- One intra-subject independent variable is the type of cheese with two levels, Cheese A (1) and Cheese B (2).
- The other intra-subject independent variable is the tasting round with three levels: blind tasting round (1), expectation tasting round (2), and informed tasting round (3).
- The dependent variables are five quasi-symmetric variables from 1 to 7 depending on how much the consumer liked the two cheeses over the three tasting rounds. Thus, the dependent variables are: Flavour, Smell, Texture, Aftertaste and Overall impression scoring each dependent variable according to a quasi-symmetric scale from 1 to 7.
- All subjects of the experiment will taste cheese A and cheese B in the three planned tasting rounds evaluating in each of them the five attributes: Flavour, Smell, Texture, Aftertaste and Overall Impression scoring each dependent variable according to a quasi-symmetric scale from 1 to 7.
- We expect a small medium size , the significance level is fixed at 5%, the power is set at 0.8
I need you to calculate the sample size needed to carry out such a study.
Could you help me know if I am using the correct test?
I'm using the next code in R:
wp.rmanova(ng = 2, nm = 3, f = 0.25, nscor = 1, alpha =
0.05, power =0.8, type = 2)