<p>Why wouldn’t you <em>expect</em> your scores to go down temporarily?</p>
<p>Between birth and now, you’ve read a certain amount of “written English” and it has given you an “ear” for the language that is not perfect, but is reasonably good, right?</p>
<p>But your skills at applying explicit grammatical rules are not very good. At least, they’re not as good at your skills at figuring this out by ear. Did you expect that they would be?</p>
<p>When you started taking practice tests, you were using your reasonably good ear for the language, and you got reasonably good scores. But apparently you were not great at telling when your ear was failing you.</p>
<p>So now you’re trying to apply rules, not just on the questions where your ear fails you, but on questions that you would have gotten right if you’d done them by ear – and sometimes you are not applying the rules successfully. Well, your ear is better than your mastery of the formal rules, so your scores are going down.</p>
<p>What you need is to (a) improve your ability to apply formal rules, (b) let your mastery of the formal rules improve your ear, and (c) become skilled at telling when your ear is good enough. You’re already working on (a), and you don’t seem to be doing anything to see whether you’re accomplishing (b) or (c).</p>
<p>If I were you, I’d start working problems twice. First, by ear. (I would also keep track of which questions I wasn’t sure of, when I was doing it by ear.) Second, trying to figure out the answer by applying the rules. I would time myself both times, but I wouldn’t stop when a certain amount of time had elapsed. I would then look at my scores from the first time through the test and see whether <em>those</em> were improving compared to the ones I had taken by ear. I would look at my scores from the second time through the test and see whether <em>those</em> are improving compared to when I started studying grammar. But comparing scores from the second time through the test to the scores I’d obtained operating on instinct before I started studying grammar wouldn’t tell me much that was useful.</p>
<p>In addition to going through explanations of grammar followed by practice sentences, I would, of course, also be practicing using the rules of grammar that I was learning on sentences that just came along: any that someone happened to say that struck me as interesting (and because “spoken English” uses different rules, people will happen to say an awful lot of sentences that are good practice for “fixing” using rules), or any that were complicated enough that I came across when reading skilled writers. (Actually, I do this now, just to improve my mastery of “written English.” It helps.)</p>
<p>Then when my test date approached, I’d look at whether I was getting better scores doing everything by ear, doing everything by applying the rules I’d learned, or doing things by ear but then applying the rules to the sentences I wasn’t sure about. I would also look at roughly how many questions I could afford to apply rules to without running out of time. Given that information, I would choose a strategy that seemed to offer me the highest score achievable in the time I was allowed.</p>
<p>But no, I wouldn’t feel at all desperate if my scores were going down as I began to learn and use a new method. I would expect that to happen.</p>