Council, 2001b). The next evolution of models most likely will incorporate what are called “Bayesian inference nets” to construct appropriate theory-driven interpretations of complex test performance (Mislevy, 1996; National Research Council, 2001b).

A third example traces the history of inquiry into the role of phonological awareness, alphabetic knowledge, and other beginning reading skills. This research has generated converging evidence that phonological awareness is a necessary, but not sufficient, competency for understanding the meaning embedded in print, which is the ultimate goal of learning to read.

Research on the role of phonological awareness and alphabetic knowledge in beginning reading began at the Haskins Laboratories in the 1960s under the leadership of Isabelle Liberman, a psychologist and educator, and her husband, Alvin Liberman, a speech scientist. At the time, Alvin Liberman and his colleagues were interested in constructing a reading machine for the blind. They made important observations about the production and perception of speech that they hypothesized might be related to the development of reading. Most pertinent was the observation that speech is segmented phonologically, although the user of speech may not consciously recognize this segmented nature because phonological segments are merged together during speech production (A.L. Liberman, Cooper, Shankweiler, and Studdert-Kennedy, 1967). So a word like “bag,” which actually has three segments represented at a phonemic level, is heard as one sound as phonological segments are merged together in speech.

Isabelle Liberman subsequently applied these observations to reading, hypothesizing that the phonetic segments of speech that are more or less represented in print might not be readily apparent to a young child learning to read (I. Liberman, 1971). It had long been recognized that teaching the relationship of sounds and letters helped children develop word recognition capacities (Chall, 1967). What was unique about the Haskins research was the clear recognition that written language is scaffolded, or built, on oral language and that literacy is a product of long-established human capabilities for speech (A.M. Liberman, 1997). But speech is usually learned naturally without explicit instruction. In order to learn to read (and write),