Correct

Correct. When the comparison groups are not equivalent,
such as in the use of a natural control group, then pretest and
posttest measurements are typically used. These measures
allow us to observe pretest-posttest change in the groups. If the
experimental group changes and the non-equivalent control
group does not, or if it changes in the opposite direction, then
that gives us some basis for drawing a causal inference about
the effects of our treatment on the experimental group.