Educational Defeat Devices


The Volkswagen Emissions Test Defeat Device needs no introduction:

Full details of how [the defeat device] worked are sketchy, although the EPA has said that the engines had computer software that could sense test scenarios by monitoring speed, engine operation, air pressure and even the position of the steering wheel.
When the cars were operating under controlled laboratory conditions – which typically involve putting them on a stationary test rig – the device appears to have put the vehicle into a sort of safety mode in which the engine ran below normal power and performance. Once on the road, the engines switched out of this test mode.
The result? The engines emitted nitrogen oxide pollutants up to 40 times above what is allowed in the US.
BBC News 4/11/15

This perceptive post from cavmaths shows , I think, the danger of relying on widely used educational “best practice” short cuts. They can actually be deleterious to student understanding. In short, many of them are simply “educational defeat devices”, clever tricks designed to give a false impression of student performance under artificial test conditions, cheats that fall apart when tested in the real world.

One thought on “Educational Defeat Devices

  1. Requires Improvement November 23, 2015 / 11:54 pm

    During a boring 45 minutes watching my class do a test today, I tried to work out why teachers prepping pupils for exams were different and better than what VW have been up to. Mainly because my department would struggle to pay an $18 billion fine, when our main asset seems to be slightly stale digestives.

    I’m not sure I came up with a convincing, watertight answer. Not loading a test car with lots of suitcases before a fuel consumption test is OK, but having a separate defeat device blatantly isn’t. Some revision and exam prep is OK, but too much isn’t. What I can’t do is put my finger on a point where “OK” becomes “not OK”.

    At some point in the past, I don’t think that mattered; individuals could use their conscience/judgement, and everyone stayed quite a way from the moral edge anyway. In the current climate, I don’t think that’s enough…

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