Comment by e12e
6 years ago
It might be somewhat safe to take a poor test result as correlating with poor knowledge on a subject.
And it might be safe to assume a high test score is repeatable.
The challenge is to find a test that correlate high scores with good knowledge - not merely with being good at taking tests.
Because rarely do we care about how good someone is at taking tests; we'd like to measure how good their knowledge is. That's hard to do if we only can infer poor knowledge from a poor test result, but not good knowledge from a good test result.
A perfect system is hardly necessary. Just a good system. Tests have worked for a thousand years. People wouldn't use them if they were useless.