title: Major alternatives to the Classic Experimental Design.
abstract: In summary, giving up any of the three defining features of the Classic Experimental Design has (at least) two important effects. Each concession creates a significant threat to our confidence that any improvements observed were actually attributable to the treatment we are studying. At the same time, each concession opens a door by enhancing, sometimes greatly, the feasibility of conducting work in settings that are the most true to everyday clinical practice. When the work is thoughtfully and responsibly conducted, the alternative designs can contribute to clinical knowledge in a way that is equally important to the contributions made by work that conforms to the stringent requirements of the "Classic" design. In the next article, we will discuss single-time-point designs, along with the important dictum, memorized by most everyone who has taken a course called "Introduction to Research" or "Introduction to Statistics" that correlation is not causation.
authors.affiliation: School of Social Work, University of Pittsburgh, USA. greenocg@msx.upmc.edu
authors.forename: Catherine G
authors.initials: CG
authors.lastname: Greeno
mesh_terms: D002986:Clinical Trials as Topic / Q000379:methods*; D005069:Evaluation Studies as Topic; D006801:Humans; D012107:Research Design