Generalization:

Once the student performs well on one assessment, are you arranging opportunities for the student to practice new assessments (with different question types, number of questions, formats, presentation modes – paper-based versus online)?  

Are you arranging opportunities for the student to practice the targeted skill in natural environments and under natural conditions?

Consider the conditions under which the student would take a real pre-employment screening assessment (e.g. at home, in a library, at a kiosk within the place of potential employment, in an office at the place of potential employment).

Keep in mind that many pre-employment screening assessments are presented online.  Would you be sitting with him as he takes these assessments?  In all likelihood, no.
Some assessments are timed.  If the student will not seek accommodations under ADA, be sure to arrange opportunities for the student to practice these assessments under timed       conditions.  It may also be necessary to identify strategies to use in the case of a very frustrating technological issue during testing (e.g. computer freezes, internet connection goes down).

Have you adapted visual supports so that they can remain in the natural environments that this student encounters now, and in the future?

Just before the student takes an assessment at the place of business, can he refer back to    a visual reminder cue that summarizes key issues (e.g. red flag responses to avoid)?  Does he need to review the steps he should follow to “attack” each question (presented      on a visual reminder cue)?
If he takes an assessment at home, can he refer to these visual cues as he takes the test?

Are you collecting data to make adjustments to your teaching and to ensure that the student is performing well on these practice assessments across multiple conditions?