I've got several variables in a dataset of which I'm not really sure what type of data they are: nominal or ordinal.
Context: the variables are part of a dataset in which each case a student. Of those students 100 were part of an experimental group, while 51 were part of the control group. The analysis I want to perform is to test the hypothesis that the experimental group performed better then the control group. Therefore I need to establish the correct types, nominal or ordinal, to determine which statistical tests I might run to test the hypothesis.
The first variable can take three possible values:
0 (indicating 'wrong answer given on question X') 1 (indicating 'partly correct answer given on question X') 2 (indicating 'correct answer given on question X')
My doubts here: I believe we can only define a variable as ordinal when a certain order can be established. I think we can: 0<1<2. Is this correct reasoning?
Second variable holds two possible values:
0 (indicating 'wrong answer given on question Z') 1 (indicating 'correct answer given on question Z')
My doubts on this one: if I recall correctly, variables with only 0 and 1 are usually nominal. But aren't 'right answer' and 'wrong answer' not possible ordinal values, since 0<1?
So my question here is: for each of those variables, should I tread them as nominal or ordinal?