Educators at all levels are concerned with thedevelopment of their students? critical thinkingskills. But how can we reliably measure any change inthis ability, and how long does it take? This booksummarizes the results of a two-year investigation ofcognitive development in college students. Studentperformance on exams at different levels of Bloom'sTaxonomy was used to estimate improvement inhigher-level thinking. The California CriticalThinking Skills Test (CCTST) was used as anindependent and discipline-neutral estimate of thisability. Data analysis confirmed the cumulativehierarchical relationship of Bloom?s, with studentsaveraging 73% on exam questions at the knowledgelevel and 53% at the application and analysis levels,although statistically significant improvement incritical thinking by students was not detected overtwo semesters. Clearly, critical thinking isdifficult for students and takes longer to developthan we might have guessed. The findings of thisstudy have implications for curriculardecision-making and course management, and arerelevant at an institutional and an individual courselevel. ukryj opis