If students are prepared to spend time creating and recording samples to use in a composition it is similar to a student setting up a prepared piano or a particular set of percussion instruments for a piece. This is a part of the creative process. The software is then a tool for realising what they are striving for and should be assessed as such.
The use of samples from other sources eg existing pop records, has other implications including copyright and originality. If a student used a sample, such as the opening bass riff to 'Under Pressure', would this covered by the examination boards requirement to acknowledge sources of quotations in a composition?
Trevor