Broadly speaking, a risp may be used in three ways:

to introduce a topic

to revise a topic, or a number of topics

An introductory risp is specifically designed to give a pathway into new theory.
The hope is that by starting to ask for themselves some of the questions that the theory is intended to answer,
students will be prepared for the exposition that is to follow.

A consolidation risp provides good practice in the use of skills while attempting to answer some wider question.
This type of risp will assume some relevant theory to have been previously studied.
A consolidation risp will generally be a good revision risp as well.

A revision risp is akin to a consolidation risp, but is likely to be more synoptic,
drawing together bits of theory from a range of topic areas.
This means that careful consideration needs to be given over when to use such a risp:
are all the required skills in place?

The Teacher Notes always begin with a suggestion about the most appropriate use for each risp.
You are of course free to disregard this suggestion (!)