STRONG INFERENCE John R. Platt Science. 146, October Arin Tuerk October

Steps of Strong Inference (Francis Bacon) 1) Devising alternative hypotheses 2) Devising a crucial experiment (or several) with alternative possible outcomes which will each exclude one or more of the hypotheses 3) Carrying out the experiment as to get a clean result 1’) Recycle the procedure using sequential hypotheses to refine the remaining possibilities “Any conclusion that is not an exclusion is insecure and must be re-checked”

LOGICLOGIC What came out of the box?? A Pen My cell phone Gum Something long and thin Something Rectangular Something tiny A Pencil A CalculatorA hair tie When a field is well defined,

LOGICLOGIC What causes an Eating Disorder? What causes Depression? What causes Anxiety? Can SI be applied to social sciences? -always more alternative hypotheses -interactions of hypotheses -is it only because it’s a newer field?

“The moment one has offered an original explanation for a phenomenon which seems satisfactory…affection for [one’s] intellectual child springs into existence, and as the explanation grows into a definite theory [one’s] parental affections cluster about [the] offspring and it grows more and more dear …. There springs up also unwittingly a pressing of the theory to make it fit the facts and a pressing of the facts to make them fit the theory” (Chamberlin,1897) HaHa HaHa HbHb HkHk

No one likes a Pathological Scientist It’s tempting to reinterpret results in favor of your hypothesis Not Pseudo-science, no dishonesty involved, just a lack of understanding of the power of subjective effects and wishful thinking Unconsciously ignore counter evidence Don’t let this happen to you! Develop clear hypotheses and choose appropriate statistical tests BEFORE you examine the data Don’t fall into habit! Never lose the intentional aspect of your work. Be problem-oriented, not method-oriented Continually tie your work to your original questions

99% of Statistics are made up… – Mathematical support is valuable but is no substitute for logical reasoning Mathematical vs. Logic box Correlations falsely lead to causal evaluations Power Exam Question “We have come to like our habitual ways and our studies that can be continued indefinitely. We measure, we define, we compute, we analyze, but we do not exclude. And this is not the way to use our minds most effectively…”

Test Early, Test Often. isprovable heory Driven ystematic

Fermi’s Notebook -pick up dry cleaning -get milk -half an hour to an hour of analytical thinking and logical tree drawing -new Gilmore Girls ep!