Grade (un)reliability - the full story


Over the last few weeks, I've been working on a document that tells the full story about grade (un)reliability, including

* why grade reliability matters

* the problematic nature of the quest for the 'right' mark

* the distinction between 'accuracy' and 'reliability'...

* ... and how grades can be unreliable even when marking is technically perfect

* the 'lottery-of-the-first-mark'

* the inherent 'fuzziness' of all marking

* how to measure fuzziness

* the evidence about how (un)reliable grades actually are

* some simulations of 2018 A level Biology and 2018 GCSE English Language

* a description of 21 possible ways to deliver reliable grades (some of which work better than others...)

* ...and an analysis of why double-marking doesn't work at all

* some implications of the various possibilities

* a full analysis of the statistics of marking and re-marking.

Much of the content has appeared elsewhere, in bits; this document brings (I think) all the main things together into a single place.

The document is long (!!!), but I trust well-structured; please do be in contact of you have any thoughts, questions or suggestions, and especially if you disagree with anything - and indeed if you find any mistakes (which are my fault, and for which I apologise in advance!).

To read or download the document, please click on "School exam grades are unreliable" below...



School exam grades are unreliable
.docx
Download DOCX • 11.77MB

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