Introduction of Single Subject Designs as New Experimental Designs. (III). Internal validity and external validity.

External, Internal and Construct Validity

Introduction In research, validity refers to the degree to which findings are applicable in real-life situations. Essentially, if the findings are strongly valid, it implies that they have an excellent degree of applicability. In contrast, low validity implies that the survey is not applicable in real-life situations. The specific approach used during research has strong influence on validity. ...

Establishing the internal and external validity of experimental studies.

The information needed to determine the internal and external validity of an experimental study is discussed. Internal validity is the degree to which a study establishes the cause-and-effect relationship between the treatment and the observed outcome. Establishing the internal validity of a study is based on a logical process. For a research report, the logical framework is provided by the rep...

JMASM 32: SAS Template for Single-Subject Experimental Designs

Internal and external validity of cohort studies.

I participated with pleasure in discussions on 30 September 2011 in Warsaw during the ‘Diff erences in Health in the Polish population’ Conference, which aimed at critical assessment of fi rst baseline results from the PONS study, a pilot prospective cohort established in Poland. Th e PONS study results from the ‘Closing the Health Gap’ Report recommending an attempt to start building in Centra...

Single - Case Experimental Designs

Single-case experimental designs are characterized by repeated measurements of an individual's behav­ ior, comparisons across experimental conditions imposed on that individual, and assessment of the measurements' reliability within and across the con­ ditions. Such designs were integral to the develop­ ment of behavioral science. Early work in the field of psychology depended on the analysis o...