The Comprehensive Test of Phonological Processing (CTOPP) assesses phonological awareness, phonological memory and rapid naming. Persons with deficits in one or more of these kinds of phonological processing abilities may have more difficulty learning to read than those who do not. The CTOPP was developed to aid in the identification of individuals from kindergarten through college who may profit from instructional activities to enhance their phonological skills. Because the test battery spans such a wide range of ages, and the abilities it taps are so varied across the ages, it was necessary to develop two versions of the test. The first version, developed for individuals ages 5 and 6, contains seven core sub-tests and one supplemental test. The second version, for individuals ages 7 through 24, contains six core subtests and eight supplemental tests.