has part is about has_specified_input has_specified_output achieves_planned_objective data set data transformation test of association between categorical variables false positive rate association between categorical variables testing objective study group population categorical variable family child-parents trio transmission disequilibrium test 2 Orlaith Burke Alejandra Gonzalez-Beltran Philippe Rocca-Serra STATO , adapted wikipedia (from http://en.wikipedia.org/wiki/Transmission_disequilibrium_test), polled on June,2013 TDT The transmission disequilibrium test is a statistical test for genetic linkage between genetic marker and a trait in families. The test is robust to population structure. p-value pending final vetting