Abstract: This review of research generates principles for the design of instructional programs that incorporate technology to foster critical-thinking dispositions. The dispositional aspect of critical thinking may be considered part of attitudinal memory, readily activated if sufficiently strong. We describe evidence suggesting that ill-structured problem solving can provide learners with motivating activities that strengthen critical-thinking dispositions, thus fostering the sensitivity to occasion and inclination for engaging in critical-thinking practices. The Jasper Series is reviewed as a program for mathematics learning that incorporates five important attitude-strengthening elements (Fazio, 1995) into ill-structured problem-solving activities. Evidence is provided to demonstrate how the design of this program provides activities that promote critical-thinking dispositions.