V N Vimal Rao, Jeffrey K Bye, Sashank Varma
The psychological reality of the learned "p < .05" boundary
Cognitive research: principles and implications
genetic conditions associated neurodevelopmental disorder gcand developmental domains motor ability thinking learning social abilities communication potential intervention targets performance measures developmental concepts expressed using several types scores normreferenced scores intended diagnostic context allowing identification impairment relative agebased expectations exhibit dramatic floor effects used individuals significant limitations person ability scores derived via rasch analysis item response theory available many standardized tests intended measure withinperson change however used evaluated primary endpoints gcand clinical trials study simulated series parallelarm clinical trials several chronological age impairment conditions compare empirically power type error rate operationalizing test performance using ability scores rather normreferenced scores using vineland adaptive behavior scales example demonstrated advantage statistical power ability scores normreferenced scores extreme levels impairment advantage least partially driven floor effects normreferenced scores simulated conditions impairment less severe ability scores outperformed normreferenced scores similar type error rate closely approximated nominal type error rate 5 scores results simulation demonstrate substantial power interpretative advantage ability scores normreferenced scores studies gcand enroll participants high levels impairment results expected generalize studies developmental concepts regardless etiology specific test however relative advantage ability scores expected even greater tests higher floor vineland