Evaluation is a bit harder. In academic circles, evaluation means to judge the worth,
usually by comparing a thing to some kind of standard. In the case of evaluating
an article, that standard would be other articles in the same discipline or journal as
the one you’re reading. If you are not familiar with those other articles it may be
hard to evaluate well. You can, however, do a fairly good job of it by considering
the stylistic and structural conventions of other, similar articles. Does this one fit
the pattern? Does it measure up to the academic standards of writing, presentation,
organization, source citation and such? Sometimes even those questions can be hard
to answer but they should be attempted. The answers will give you some ammunition
for your critique.