The purpose of this paper and its sister paper I (Farrell and Hooker, a) is to present, evaluate and elaborate a proposed new model for the process of scientific development: self-directed anticipative learning. The vehicle for its evaluation is a new analysis of a well-known historical episode: the development of ape language research. Paper I examined the basic features of SDAL in relation to the early history of ape-language research. In this second paper we examine the reconceptualization of ape-language research following what many conceived to be Terrace's refutation of ape-language. We show that the apparent ‘revolution’ in our understanding of ape linguistic capacities was not based upon ‘revolutionary’ research different in kind from ‘normal’ research. The same processes of self-directed interactive exploration of possibility space, that enables a homing-in upon both error and success, is present in all phases of productive science. Moreover, conceiving science as an SDAL process explains how scientists learn how to learn about their research domain.