Accurate and insightful assessment is the key to success.
Students are usually admitted to selective schools, colleges, universities or particular courses largely on the basis of previous examination results.
This is a very partial and patchy way of assessing ability and potential, but it is the cheapest.
Teachers and lecturers then assume that the group in front of them shares similar ability and background knowledge, and this works reasonably well for the majority most of the time.
We all know, however, that many individuals do not quite fit the mould.
There are all sorts of neat schemes and tests available which clain to assess people's potential and learning styles, but, in the end, there are no short cuts. There is no substitute for spending some time assessing a learner's particular qualities and needs in detail and on an individual basis.
Accurate assessment depends on slowly acquired experience, insight and knowledge.
This is just one of the services