Forced to give grammar tests?

Diane from foreignlanguagefun.com left me this comment on my previous post:

"I teach using immersion, stories, TPR, music . . . but then I have to give common assessments. Although they are proficiency-based, there is a lot of isolated grammar, etc. I'm fascinated by the "no warning" tests. Of course, it makes perfect sense and is a much more valid assessment piece. Yet, it's still completely outside the "way things are done" --at least here in my public high school. When I taught at a private middle school, I had more freedom. How did you make the shift? School & parents supportive? I know your methods work, but how do you get others on board?"

I got a similar question when I gave a session called Assessing Comprehension without English and this fall's KWLA conference. For one thing, it makes me realize how fortunate I am to work with people who trust me to run the Spanish program the way I choose, so I was able to reject using the curriculum tests and workbooks last year, and this year rejected the textbook altogether. I didn't know quite what to answer, but what I said was this: Fight for it. I've never taught in a public school, so I don't know if you can even do this, but I'd call the administrator on the fact that he or she has no idea what language acquisition entails and therefore has no right to impose assessment judgments on you. Language isn't learned like any other subject, and you can't test it that way.
Other suggestions:
See if the department will let you use their test, but modify it to fit a more communicative approach. Can you change a question to elicit the same target feature (i.e. the form digo) by asking a communicative question instead of giving a multiple choice?
See if the department/administration will let you alter the weighting of the test. Can you weight the common tests lower and supplement with your own communicative tests?

To answer the other question, I shifted from announced tests to pop tests quite abruptly. I heard a couple of teachers mention it at a TPRS workshop at the 2007 KWLA conference, and I implemented it the very next week. I just told the kids that I wasn't going to tell them when tests were anymore. But I promised that I wouldn't put anything on a test that I hadn't asked several times in class in several different ways, and I always promise my students not to have unrealistic expectations of them. At first they threatened to mutiny, lol, but they got over it. Every once in a while they'll bring it up. This week one of my Spanish 3 cherubs was working on a test and said, "You know, in every other class, the teachers tend to let us know when tests are coming..." But he was joking and trailed off. They know it's not going to change. And parents have been nothing but supportive. Most of the students have also. Really, it's amazing how you can win people over when you have all the logic on your side!