I can't find where I read it, but a
research group found a totally reliable test that predicts hard working
dependable workers. They wouldn't describe the test for fear of making
it useless. They said that it included a small paragraph of
instructions that required the test taker to stop and read the
instructions before answering the simple multiple choice question.
Test takers who read the instructions carefully knew exactly which
response to choose (D), everyone else picked an obvious one of the other
multiple choice answers (A). The ones who read the instructions carefully
(D) were 100% predictably the "hard working dependable workers."
I
came across just such good predictors in my first year of doing
marketing research. I was at the Bank of America working with an
economist. We were using an IBM card sorting machine (called a
computer in those days). We were comparing personal loan and credit
applications of a pile of people who turned out to be good credit versus a
pile of people who turned out to be bad. We developed an equation with
about four variables that was a near perfect predictor of credit
outcomes.
This was the first use of a credit scoring system that I know of and Bank of America sold our work widely in the industry. What I can tell you now is that there were two elements, in 1964, that combined to give a 100% certainty in predicting credit outcomes. One was whether the applicant put a telephone number in the space provided for a telephone number on the application and the other was whether the applicant filled in all the blank spaces on the application. Failure to do either was a sign of a future bad loan. Of course failure to put in a phone number automatically put the applicant in the category of not filling in every space.
The equation was used widely and I doubt most credit scoring companies ever knew the underlying elements of the equations we used. Had people known the underlying elements of credit scoring they would have known how to get a perfect score.