At the time of writing this, I’m moderating some work uploaded for the IA (visual arts exhibition) component for the November examination session, which means spending a lot of time scrutinizing artworks on multiple large screen monitors and also scrutinizing the words of the visual arts assessment descriptors (which I probably know by heart by now). Sometimes I very quickly come to a decision about the most appropriate mark, but quite often I see a range of achievement in different elements in different criteria…

And then I think about ‘best-fit’.

Criteria descriptors

As a student you may never have heard of the ‘best-fit approach to assessment’ but really its integral to working out how many marks I give for each criterion. As you probably do know, each criterion comprises a set of level descriptors.

Each level descriptor is worth one or more marks (e.g. for a mark of 4, 5 or 6 for Conceptual Qualities, the descriptor reads ‘The work visually elaborates ideas, themes or concepts to a point of adequate realization and demonstrates the use of imagery, signs or symbols that result in adequate communication of stated artistic intentions.’ )

Obviously the descriptors get a little more demanding in relation to the more marks that are available, so to get 7, 8 or 9 marks for Conceptual Qualities the language refers to effective rather than adequate realization, and ‘the subtle use of complex imagery, signs or symbols’ rather than just ‘the use of imagery’ etc.


But how do you – and your teacher – work out if the mark is, say, 5, 6, 7 or 8?

The IB say, ‘A best-fit approach is used to ascertain which particular mark to use from the possible range for each level descriptor. The aim is to find, for each criterion, the descriptor that conveys most accurately the level attained by the student, using the best-fit model.’

You, your teacher (and moderator) use this best fit approach to marking.

This means that the teacher awards the upper marks if your work demonstrates the qualities described to a great extent; in this case, the work may be close to achieving marks in the level above.

For example, if there is evidence of a little complex imagery and/or or sophisticated thinking, but this is not seen throughout the exhibition, the mark will probably be 6/9.

If there is more than a little, but its still not consistent or generally apparent, the mark may go up to 7/9.

Conversely, your teacher awards the lower marks if your work demonstrates the qualities described to a lesser extent; the work may be close to achieving marks in the level below. So, if some ideas are not really elaborated (visual elaboration) or some of the images are a little obvious, but these are the exception, the mark could be 4/9.

Best fit means carefully considering achievement as a whole for each criterion; so for criterion C this could be weighing up degrees of elaboration and subtle or complex thought, as opposed to degrees of more superficial or less sophisticated thought and ideas, and coming up with a justifiable mark that accurately reflects overall achievement.

Its complicated, but thankfully the more you do the more familiar the process becomes.

If you as a student can spend even a little time thinking about ‘best-fit’, and how to maximize marks for your artwork in all components, this will be well-spent and worthwhile time.