Project scheduling "99" rule

The actual project scheduling rule goes like this:

"The first 90 percent of the task takes 10 percent of the time. The last 10 percent takes the other 90 percent."

The way we always said it was:

"The first 90 percent of the task takes 90 percent of the time. The last 10 percent takes the other 90 percent."

This is true of students. Often we can get them 90% of the way there but we don't have the time to get them the remaining 10%. That remaining 10% is found through practice and investigating the concept in a variety of contexts. I'm gaining an appreciation of the well written investigation that goes some of the way to assisting students gain this understanding.

For instance, we recently completed an investigation on radians. By the end of the investigation, students had worked through a variety of uses of radians, applied formula in a variety of ways and had to think about what the formula was comprised of and how it was derived.

This though is rarely done in lower classes - and is a real flaw in use of texts. If questions are presented in method-> practice exercise form, students rarely have to think about what is required to solve a problem. This causes a lack of retention and poor examination results (if examinations are done at all).

I've been thinking that a revision week may have their place in the programme, once a term where students are forced to reconsider earlier work with an element of training how to revise for exams.

I will think on this further.