ABSTRACT
Introduction .................................................................................................................................... 370 The Need for Improved Experimental Design............................................................................... 371 Basic Statistical Considerations ..................................................................................................... 371
First Steps: Ethical Considerations ........................................................................................... 371 Observational and Epidemiologic Studies ................................................................................ 372 Randomized Controlled Experiments ....................................................................................... 372 Basic Principles of Statistical Inference.................................................................................... 373 Types of Data ............................................................................................................................ 374
Data Distributions ................................................................................................................ 375 Computer Software ................................................................................................................... 375 Laboratory Animals as Models of Humans or Other Species .................................................. 376
Experimental Design ..................................................................................................................... 377 The Experimental Unit.............................................................................................................. 377 Formal Experimental Designs .................................................................................................. 377 Factorial Designs or Treatment Arrangements ......................................................................... 378 A Well-Designed Experiment ................................................................................................... 378
Avoid Bias ............................................................................................................................ 378 Have High Power .................................................................................................................. 379 Have a Wide Range of Applicability: The Factorial Experimental Design .........................380 Be Simple .............................................................................................................................380 Be Capable of Being Analyzed Statistically ........................................................................380
