Excellent introduction to the field of testing.
Don't be turned off by the fact that this (the fifth edition: 1990) is no longer the current edition.
Although some recent developments (eg. Item Response Theory) are treated lightly, this is an excellent introduction to the field of testing (both in psychology and education) from L. Cronbach (as in "Cronbach's alpha"), who was one of the preeminent authors of the field.
