Hi Darcy. These evaluations are basically questionnaires. The assessment is determined by your answers to those questions. We would talk and determine which assessment is best for you based on your issues/needs. I can then direct you to the appropriate lifestyle changes, supplements and/or diet modifications. The time to complete the evaluation is minimal; maybe 15 minutes done online. I think the accuracy question is best answered with it’s a good way to start to get some general understanding of what is going on with you. Often times, one evaluation will lead to another. I hope this helps.