T he evaluation of CALL from the perspective of gross comparisons of CALL versus classroom learning outcomes is an approach unlikely to shed light on the problem or solution of instructed SLA. It creates an irony wherein the most sophisticated modern tool is investigated through the most crude and outdated educational research methods (Chapell 2005)This paper reviews current methods of evaluation of CALL as an instructional solution to the problem of instructed SLA, on the basis of theory of conditions (cognitive and socio-affective) that ideally should be created for optimal/successful learning environments and effective task-based instruction.Evaluation of CALL task cannot be a categorical decision about effectiveness. Instead, it results in an argument indicating in what ways a particular task is appropriate for particular learners at a given time, i.e., CALL task appropriateness. CALL task evaluation denotes three levels of analysis: CALL software, teacher-planned activity, and learners' performance during activities. Evaluation argument is constructed on the basis of both judgemental and empirical analyses. The former examines characteristics of the software and t/task while the latter addresses the details of CALL taskuse and learning outcomes in terms of principles /criteria drawn from theory and research on conditions for instructed SLA. The criteria for CALL appropriateness are applied in view of the stated purpose of a CALL task at various stages of instruction.    Examples of CALL task evaluation, a judgemental as well as an empirical research tasks/activities, are provided.