A model that has
been shown to be useful comes from The American
Psychological and Education Research Associations, who
identified five sources of validity evidence: (1) content,
(2) response process, (3) internal structure, (4) relations to
other variables and (5) consequences (Downing 2003;
Beckman 2004; Boor et al. 2007; Fluit et al. 2010; Boerboom
et al. 2011a, b) (Box 1).