Preparing for test day
The ASLPI is not a test for which you study. As with all languages, skills develop over time and that time frame varies from person to person. To improve your ASL skills, a combination of formal instruction, diagnostic assessment to identify specific strengths and weaknesses, and interaction with proficient users of the language in a variety of communicative contexts is needed. However, none of these produce "overnight" changes in your skills. As with any test, you are encouraged to do things to reduce test anxiety, such as eating well, exercising, and getting a good night's sleep before the day of your ASLPI evaluation.
In proficiency testing, examinees will always be asked questions for which they are not prepared. This is because the interviewer's job is to elicit a sample of the highest language proficiency of which the examinee is capable. Probing into linguistic areas for which the examinee is not prepared finds both the maximum skills (ceiling) and limits (floor) of the examinee's ability. Each evaluation must cover as wide a range of topics as possible and the discussion is conducted in such a way that the evaluation team has a chance to observe the examinee's flexibility in language structure and vocabulary across a range of topics, both familiar as well as complex and critical. A range of topics and random change in topic is also essential to evaluate flexibility of comprehension.