You should allow 1-2 hours to complete the 20-35 questions given during the assessment. The exact number of questions will vary due to the adaptive mechanism. It is likely that you will be asked questions on material you have not yet learned. On such questions it is appropriate to answer, "I don't know." On any question that you have familiarity with, however, it is important to do your best. "I don't know" is interpreted by ALEKS to mean that you do not know the topic, and this will be reflected in the assessment results. If you do not do your best on the assessment, ALEKS will underestimate your knowledge.