CALL evaluation might ideally draw on principles from fields such as second language acquisition, language pedagogy, instructional design, and testing and measurement in order to make judgments about criteria such as elaborated input, feedback, collaborative learning, authentic tasks, navigation, screen design, reliability, validity, impact, and practicality. In this study, a subset of criteria were used to evaluate the design of English as a second or foreign language (ESL/EFL) online courses and assessments, Longman English Online. This article illustrates how a set of principles suggested evaluation criteria which, in turn, suggested particular variables for the instructional design; these variables, again in turn, suggested potential operationalizations which could be implemented as task features in CALL materials. Results of the judgmental evaluation indicated that most of the criteria were met, although some better than others.