Hi Hector- Thanks for your post to the forum. That's a very good question and one I had to really think about. I use open book tests when the knowledge I am assessing involves material that realistically is not memorized. The student however, needs to know how to find that material quickly in the manual or text. This also assesses how well the student has read the material to know how/where to find the necessary charts, rules, codes etc. Bottom line is, I think that the open book quiz serves one purpose and the closed book quiz another. Both can be effective assessment methods. Best wishes- Susan