How persuasive is a good fit? A comment on theory testing.

@article{citeulike:2953186, abstract = {Quantitative theories with free parameters often gain credence when they closely fit data. This is a mistake. A good fit reveals nothing about the flexibility of the theory (how much it cannot fit), the variability of the data (how firmly the data rule out what the theory cannot fit), or the likelihood of other outcomes (perhaps the theory could have fit any plausible result), and a reader needs all 3 pieces of information to decide how much the fit should increase belief in the theory. The use of good fits as evidence is not supported by philosophers of science nor by the history of psychology; there seem to be no examples of a theory supported mainly by good fits that has led to demonstrable progress. A better way to test a theory with free parameters is to determine how the theory constrains possible outcomes (i.e., what it predicts), assess how firmly actual outcomes agree with those constraints, and determine if plausible alternative outcomes would have been inconsistent with the theory, allowing for the variability of the data.}, address = {Department of Psychology, University of California, Berkeley 94720-1650, USA. roberts@socrates.berkeley.edu}, author = {Roberts, S. and Pashler, H. }, citeulike-article-id = {2953186}, issn = {0033-295X}, journal = {Psychological review}, keywords = {bob, general, heather, jie, kristina, nemo, shiva}, month = {April}, number = {2}, pages = {358--367}, posted-at = {2008-07-02 20:11:38}, priority = {0}, title = {How persuasive is a good fit? A comment on theory testing.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/10789200}, volume = {107}, year = {2000} }

TY - JOUR ID - citeulike:2953186 L3 - citeulike-article-id:2953186 TI - How persuasive is a good fit? A comment on theory testing. JF - Psychological review VL - 107 IS - 2 SP - 358 EP - 367 AD - Department of Psychology, University of California, Berkeley 94720-1650, USA. roberts@socrates.berkeley.edu SN - 0033-295X N2 - Quantitative theories with free parameters often gain credence when they closely fit data. This is a mistake. A good fit reveals nothing about the flexibility of the theory (how much it cannot fit), the variability of the data (how firmly the data rule out what the theory cannot fit), or the likelihood of other outcomes (perhaps the theory could have fit any plausible result), and a reader needs all 3 pieces of information to decide how much the fit should increase belief in the theory. The use of good fits as evidence is not supported by philosophers of science nor by the history of psychology; there seem to be no examples of a theory supported mainly by good fits that has led to demonstrable progress. A better way to test a theory with free parameters is to determine how the theory constrains possible outcomes (i.e., what it predicts), assess how firmly actual outcomes agree with those constraints, and determine if plausible alternative outcomes would have been inconsistent with the theory, allowing for the variability of the data. KW - bob KW - general KW - heather KW - jie KW - kristina KW - nemo KW - shiva AU - Roberts, S AU - Pashler, H PY - 2000/04// UR - http://view.ncbi.nlm.nih.gov/pubmed/10789200 ER -