With apologies to psychometricians who may read, let me set some vernacular context for additional thoughts (prompted originally by Dan Hickey‘s, and then Alex Halavais’, writing) regarding my own thinking on badges and assessment.

It is beyond argument that we cannot crack open a learner’s head, insert a magnifying glass, and make direct, error-free observations of what the learner “knows.” Since we can’t actually take a “direct” measure of what someone knows, we collect evidence that allows us to increase or decrease our beliefs about the likelihood that they know, or are able to do, something.

Via Mark Smithers