Tag Archives: null hypotheses

The scientific wisdom of Chief Inspector Armand Gamache

Image: Books 5 – 9 in Louise Penny’s Three Pines series, featuring Armand Gamache.

“I don’t know. I was wrong. I’m sorry”.  Lacoste recited them slowly, lifting a finger to count them off.

“I need help”, the Chief said, completing the statements.  The ones he’d taught young Agent Lacoste many years ago.  The ones he recited to all his new agents.

The Long Way Home, Louise Penny

 

Chief Inspector Armand Gamache, of the Sûreté du Québec, knows a lot about homicide detection.  Gamache is the protagonist of Louise Penny’s Three Pines series of crime novels.  Over 15 novels so far, Penny has portrayed the usual assortment of crimes and their solutions, but also (unusually for the genre) Gamache’s approach to managing and mentoring the earlier-career detectives assigned to his unit.  His management philosophy can be summed up as willingness to utter, whenever appropriate, the Four Statements:

    • I don’t know.
    • I was wrong.
    • I’m sorry.
    • I need help.

These work very well for Gamache in the novels.  I’ve found they work pretty well in science, too. Continue reading

Two tired misconceptions about null hypotheses

Comic: xkcd #892, by Randall Munroe

 For some reason, people seem to love taking shots at null-hypothesis/significance-testing statistics, despite its central place in the logic of scientific inference.  This is part of a bigger pattern, I think:  it’s fun to be iconoclastic, and the more foundational the icon you’re clasting (yes, I know that’s not really a word), the more fun it is.  So the P-value takes more than its share of drubbing, as do decision rules associated with it.  The null hypothesis may be the most foundational of all, and sure enough, it also takes abuse.

I hear two complaints about null hypotheses – and I’ve been hearing the same two since I was a grad student.  That’s mumble-mumble years listening to the same strange but unkillable misconceptions, and when both popped their heads up again within a week, I gave myself permission to rant about them a little bit.  So here goes. Continue reading