Unusual kinds of answer¶
Page status: Outline
This is a rough outline of an article. It might not use full sentences everywhere and probably won’t make much sense at the moment.
When the answer is not one of the built-in data types, what do you do?
- Use the ‘closest’ built-in part type. 
- Ask for just bits of the answer, with some scaffolding, e.g. coefficients. 
- Write a multiple choice question. 
- Make a custom marking algorithm for a built-in part type. 
- Make a custom part type. 
There’s a cost/benefit calculus for making a custom part type.
If making a custom marking algorithm, make it reusable - if you spot a bug or want to make a change, you don’t want to track down every copy of the algorithm.
Think about:
- How does the student enter their answer? 
- What answers are invalid? Try to accept all reasonable efforts, but reject mistakes which might not be what the students intended. 
- How much feedback can you give? Want to explain the marking, but minimise hints as to the correct answer. Again, there’s a cost/benefit calculus for how many cases to catch. 
- Configuration options: if several questions ask the same sort of thing, use a single part type with options.