Can experimental design have only 1 group?

Question

This is where compliance is measured on all based on a teaching tool provided.

Answer 1

no, there is first the question asked, next hypothesis is created, testing hypothesis, record data, conclusion. If the hypothesis is correct, then it goes onto a theory, if theory is accepted by the general public it becomes a law. There are at least 2 groups needed, the variable (the one being tested), and the control (not tested, but its used to compare the variable)

Answer 2

no, have as many groups as you need to compare outcome potentials