In order to get you to engage the lectures, the class has a quiz at the end of each web lecture. At the bottom of each lecture you will find a "quiz" button. Hit it and take a quiz of 10 questions. You can restart a quiz and any point, take it with open book, notes or web pages.
These quiz questions count the same as an exam question. Your final grade will be based on the exam scores plus quiz scores. Not doing the quizzes will be the same as not taking an exam and subject to a failing grade. You will find that the quiz material comes from the web lectures and things discussed in class.
NOTE, you have only a limited window to take the quiz, the schedule is posted on the class web page (typically you have a few days after the lecture). Miss the date and you will be unable to take the quiz (the point of the quizzes is to get you to study before the night of the exams, hence the deadline). The quiz answers and scores are posted after the deadline. For this reason you can not submit your quiz answers late. The answers are posted and late submission will not be allowed regardless of the excuse.
Due to the large number of quizzes, it is highly likely that you will miss a quiz deadline or your dog will eat the internet the night before they are due. Thus, each student will be allowed to drop the three lowest quiz scores for the final grade. If you miss three quizzes, then those three zeros are dropped. If you answer all the quizzes on time, then your three lowest scores will be dropped.
To summarize: