Duration and Associated literature
Hour 1: 38:46
Hour 2: 41:40
Robson, C., (2002) Real world research: A resource for social scientists and practioner-researchers (2nd ed). Malden: MA, Blackwell. (Chapter 5).

Weblecture 3a
Weblecture 3b

In the first hour we start with the definitions of reliability and internal and external validity. The following aspects of internal validity are discussed: history, testing, instrumentation, regression, mortality, maturation, selection, ambiguity about causal direction, diffusion of treatment, compensatory equalisation of treatments, and compensatory rivalry.
In the second hour we present: threats to external validity and types of fixed design research. Types of true experimental design are describe, including potential threats. Among others, two groups design, three (or more) group simple designs, factorial design, matched pairs design, repeated measure design, and mixed design.Finally we discuss quasi-experimental design and sample size.