HARKing

HARKing stands for Hypothesizing After the Results are Known.

It is a form of academic dishonesty.

The Scientific Method (Ideally)

1. Form a hypothesis. ("I think A causes B.")
2. Design an experiment.
3. Collect data.
4. Analyze results.
5. Report if the hypothesis was supported or not.

The HARKing Method (Reality)

1. Collect data.
2. Analyze results.
3. Find a weird correlation. ("Hey, A correlates with C!")
4. Write the paper as if you predicted C all along. ("We hypothesized that A would cause C.")

Why It Is Bad

It destroys the ability to test theories.

If you change your prediction to match the past, you can never be wrong. You are predicting yesterday's weather.

It also inflates false positives. You are capitalizing on chance, but presenting it as a confirmed theory.

The Solution: Preregistration

Scientists should register their hypotheses before they collect data. They should post them on a public website.

This locks them in. They cannot change the story later.

The Diagnosis

If a paper's hypothesis fits the data too perfectly, be suspicious.

Science is messy. Real predictions often fail. Perfect predictions are usually written in reverse.