My thoughts re: ESL exit-testing (and testing in general)

   First, for the 2 productive skills (speaking and writing), my idea of an accurate test is to try to see whether the student can convert a non-verbal item, idea or thought into English. Suppose we're testing to see whether the student can use "let's".  Some tests will do this by saying in the directions something like "use the inclusive imperative with the following infinitives".  In this case, though, it is possible that a student may know the term "inclusive imperative" and may know how to produce it with "let's", but he/she may not fully understand in which circumstance to use it in real life.  Instead I prefer directions that attempt to set-up the situation, like "You want to go to a party, and you want your friend to go with you.  What do you say to your friend?"  If the student uses "let's" or "why don't we", or even some other expression that a native speaker might really use in this situation, it should count.  But even if the student uses "let's" but somehow goofs up the rest of the phrase so that it's nonsense, it should not count. 
   Another example would be "change these verbs from the present-tense to the past-tense.  Again, a student may have studied the forms and get the right answers.  But does he/she really know what they mean?  I suggest something like:
   Every week I go grocery shopping.
   Yesterday, I _____ grocery shopping.