When a lesson contains one or more Branch Tables the teacher should
normally set this parameter. Its value sets a lower limit on the number of
questions seen when a grade is calculated. It does **not** force students
to answer that many questions in the lesson

For example, setting this parameter to, say, 20, will ensure that grades are
given as though the students have seen **at least** this number of
questions. Take the case of a student who only looks at a single branch in
a lesson with, say, 5 pages and answers all the associated questions
correctly. They then choose to end the lesson (assuming there is that option
in the "top level"Branch Table, a reasonable enough assumption).
If this parameter were left unset their grade would be 5 out of 5, that is
100%. However, with it set to 20 their grade would be reduced to 5 out of
20, that is 25%. In the case of another student who goes through all the
branches and sees, say, 25 pages and answers all but two of the questions
correctly, then their grade would be 23 out of 25, that is 92%.

If this parameter is used, then the opening page of the lesson should say something like:

In this lesson you are expected to attempt at least n questions. You can attempt more if you wish. However, if you attempt less than n questions your grade will be calculated as though you attempted n.

Where obviously "n" is replaced by the actual value this parameter has been given.

When this parameter is set students are told how many questions they have attempted and how many they are expected to attempt.