Day 66: Test Corrections

Thursday, 13 November 2014

IMG_20141113_090131

The question. I asked student to solve for magnification.

IMG_20141113_090140

Here’s the correction for the above problem. She solved for the focal length incorrectly at the start of the problem but all other work was correct.

IMG_20141113_084252

This kid mostly got the correction right — they did indeed forget a negative sign. I felt it was bit too nitpicky of me to say that the “decimal in the wrong spot” is really a unit conversion problem.

Examples of good test corrections. I recommend building in about 20% of the test time to dedicate to corrections. That is, I build tests that should take 50 minutes plus 10 minutes of corrections.

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One thought on “Day 66: Test Corrections

  1. Pingback: Day 149: Rethinking Test Formats | Physics180: A photo-a-day blog

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