The concern that learners are not developing critical thinking skills has been ongoing for the past two decades and research suggests that undergraduate learners in the United States still lack critical thinking skills as they enter the workforce. Current ways of measuring learners' critical thinking skills are in forms of standardized exams, which do not prepare learners for future employment. In academic areas that focus on creativity, no formal way currently exists to measure critical thinking skills of learners that the design industry expects of its graduates. This research study sought to learn how performance tasks that follow a creative process based on instructional design principles can have an effect on the critical thinking skills of undergraduate art and design learners. This study used performance tasks and a grading rubric for performance assessment as a strategy to measure the critical thinking skills of 28 participants studying art and design in two 10-week blended learning courses. A quasi-experimental design was used to examine nine performance tasks that were incorporated in the virtual team creative process model, and each performance task was linked to a specific critical thinking skill by the Collegiate Learning Assessment List of Critical Thinking Skills (CLA, n.d.; Hersh, 2010). Each performance task was designed with instructional design principles in mind and was organized in a specific sequence based on elaboration theory. The performance tasks were also designed to prompt the participants to ask themselves questions when working on a design project. At the end of the 10-week course, the performance scores were assessed using a grading rubric for performance assessment that was created based on a basic rubric format and was field tested and validated by a panel of experts in the design industry prior to the implementation of the study. Using crosstabulation and Chi-Square Test of Independence, the results showed that five of the nine performance tasks had a significant effect on critical thinking skills of the participants in the quasi-experimental group. The results also indicate that by experimenting with innovative instruction and assessment tools, cultivating the critical thinking skills of undergraduate learners can be accomplished.