We secured for the Chapter step three your null theory is the one one predicts no matchmaking within variables getting examined
- Both variables need certainly to will vary with her.
- The connection must be possible.
- The cause need certainly to predate the effect eventually.
- The partnership must be nonspurious (perhaps not due to a third varying).
Just after these criteria was met, a researcher can tell he has reached good nomothetic causal cause, one that is rationally correct.