Concept Checks are intended to reinforce lecture materials and help guide your reading. I suggest completing the Concept Checks early in the week to identify gaps in your current knowledge. In this way, you will discover which areas require more of your attention and better manage your time. The checks are not designed to be a burden; thus, they are open book, open note, without time limit, and can be retaken as many times as needed. 

Successful online learning relies heavily on your participation and motivation to delve into the materials. I recommend that you read/watch the lecture materials, and attempt these Concept Checks independently. This will force you to retrieve the information from memory. I cannot stress enough how much more important the ability to retrieve and use knowledge is over simple memorization.  Attempting to search for answers on the web, will not assist you in learning biostatistics concepts and will be counter productive to the objectives of the course.