Fiducial or fiduciary – that is the question!
May 7, 2016 1 Comment
Very quickly:
A fiducial marker (noun) or fiducial for short is an object used to indicate a measurement reference point either to indicate scale or an original position or to aid more precise measurement.
A fiduciary (noun) is a person who holds a position of trust between parties for legal or financial reasons. The word fiducial (adjective) in this context indicates the actions or activities of a fiduciary.
I can see the confusion these two terms might cause. But it’s not a confusion a scientist is likely to make because we learned our words proper-like. So this leads me to think that the legal team at the DfE drew up the plans for the AS and A Level physics*. For, lo and behold, in the DfE guidance for the AS and A Level physics – students must be aware how to: 
It’s ok, one thinks, the subject specialists at the exam boards will pick it up.
AQA spec:
OCR spec:
EdExcel spec:
WJEC spec:
So once again, the DfE blunders (due in part to their desire to over-specify every part of the curriculum) will come to shape the teaching of physics students up and down the country, and they won’t know what the correct word for a fiducial marker is.
Spotted by the excellent Carol Davenport @drdav on the Twitters who is as frustrated by DfE physics blunders as I am.
*It doesn’t really, it’s probably just an administrative mistake.
Teaching science in all weather 
If you refer to the A level Geology subject criteria you will find a more useful application “use methods to increase accuracy of measurements, such as timing over multiple observations, or use of a fiducial (scale in photograph/field sketch)”