OTTER Interpreter

The text written between a pair of ### signs is interpreted by the OTTER system and not displayed to the user as it is. Instead, OTTER output is displayed. This interpretation is what allows you to write a question frame that will modify itself instead of a simple question that you have to modify manually to create variations.

Take for example a simple division question, as presented to the user. 

'Bob has 8 sweets and shares them equally with his friend Charlie. How many sweets will each boy get?'

We will now look at how such a question might be generated by a question frame. Fundamentally what we want is

(A boy’s name) has (a multiple of 2, to make integer division possible – but not too high, let’s say up to 20) sweets, and shares them equally with his friend (a boy’s name). How many sweets will each boy get?

Each time we have used brackets here, we will need to program OTTER to supply the desired text, interpreting our instructions. In OTTER the above question becomes:

And the output will be:

When presenting question text to the user OTTER will replace all sections enclosed in pairs of ### (highlighted for your convenience), with its own output, leaving other sections unchanged. How exactly this works will be the subject of this section further.