IF and TREND statements

[Jack2]

Hi there, I've recently been trying to simulate the effect of Student/Teacher ration on educational performance.

I have a converter that is called "Student/Teacher ratio" and it links to a second converter called "Quality of Learning". I'm having difficulty with the equation in the "Quality of Learning" converter. I would like to say that as the Student/Teacher ratio goes down then the Quality of Learning will go up.

I think i mite be able to use an IF statement for this but my knowledge of programming languages is limited. Any help would be greatly appreciated

Thanks

[tomfid]

Here's one very simple equation that fits the bill:

Q of Learning = k/(Student teacher ratio)

The bigger student teacher ratio gets, the smaller Q of Learning gets. k is an arbitrary constant that translates the units from students/teachers to quality. This is better than using an IF statement, because it's a continuous relationship. You'd have a hard time writing an IF statement that could handle all possible student-teacher ratios.

This might be less than satisfactory, because the shape of the relationship is not very flexible. You could try other equations, or switch to a lookup. For example, you might create an S-shaped relationship, to capture the idea that a ratio of 3:1 is almost as good as 1:1, but quality falls off quickly between 10:1 and 30:1, and thereafter 200:1 is not much worse than 100:1.

Tom