The Edocio system:
We have the learner read view or listen to one page of content from the course or textbook. Then we present the learner with 5 sentences from the course or text and ask them to identify the one sentence that was on the page of content just read or viewed. If the learner can select the correct sentence, they continue to the next page of content. If they fail and select a sentence that was not on the page just viewed, they are sent backwards to read or view the content and those who fail repeatedly are sent back farther than one page or to the beginning. Those who complete a chapter are given a code they can use to get into the next chapter. This is repeated until they reach the end of the course.
The entire program is one page of php and assorted small files for communication. There are no loops and no get or post commands so the simplest web server can serve it with extreme security. It does set a cookie but does not store any information in the browser. Learners need not log in or sign up and the system keeps no information about the student except the randome generated code used to verify learner performance.
Try it out