OpenMusings

Okay, my T224/TMA04 mark is now in, and I’ve redone my substitution sums – as I suspected, if I’d scored 85% on the final TMA, I’d have been in the position where I would have needed to score 85% – not a mark higher or lower – to get a distinction for this course, thanks to the way substitution works on courses where the TMAs aren’t all weighted equally. With the score I got on the final TMA, there’s the equally strange situation where any score over 85% on the exam will guarantee me a distinction, except 90% or 91%. Confused? Read on below the cut and I’ll try to explain…

I vaguely recall an OU student regulation that forbids talking about specific marks you’ve received on TMAs or exams – can’t find the regulation at the moment, but I’m going to play safe and be a bit vague. Here goes.

T224′s TMAs are weighted as follows:

TMA01     15%
TMA02     30%
TMA03     30%
TMA04     25%

My highest TMA score was on TMA04; the lowest, on TMA03. On TMA01 and TMA02 I had the same score – although the different weighting means they contribute different amounts to my Overall Continuous Assessment Score (OCAS).

So. The substitution score is the weighted average of your POCAS & exam score; it cannot be used to substitute any higher TMA score; and where there’s a choice of eligible TMAs, it must substitute the one that makes the lowest contribution to the OCAS. Fairly clear rules – there’s a paper worksheet to help you work it all out yourself, but both Marx and the Assessment Calculator on StudentHome will both work it out for you.

Here’s where the fun starts. In my case, once you get an exam score of 85% or over (a requirement for a Distinction, which is what I’m interested in), there are 3 distinct score ranges that produce different results:

85%-89%
An exam result in this range gives a substitution score that can only be used to replace my lowest TMA score – which conveniently was on one of the highest-weighted TMAs. End result: an OCAS over 85% and a guaranteed distinction.

90%-91%
At 90%, with a slightly higher substitution score, another TMA score comes into the substitution range – and it’s TMA01, the one with the lowest weighting (same original score as for TMA02, but because it contributes less to the POCAS because of its lower weighting, it’s the one that gets substituted) – and because of that, the OCAS is left below the 85% threshold, leaving me with a Pass 2.

92%-100%
In this range, even when applied against the lowest-weighted TMA, the substitution score is enough to guarantee an OCAS over 85%, and puts the overall result into the Distinction range again.

I can follow how the rules work easily enough, and on courses where the TMAs are equally-weighted there wouldn’t be an issue. As I’ve shown, though, different weightings can throw up some frankly silly inconsistencies. Hopefully, this is one of those circumstances where the Examination and Assessment Board can exercise a little discretion – otherwise I’ll be one very unhappy bunny should I score 90% on October’s exam…

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