Marty West and colleagues have an incredibly important study described in Education Next this week. It’s based on a piece published earlier this year in Psychological Science, a leading psychology journal, but the Ed Next version is probably easier for ed reform folks to access and grasp.
At its heart, the study applies well-established concepts from cognitive psychology to the field of education policy, with potentially unsettling results. Intelligence, or cognitive ability, can be divided into two types: crystallized knowledge and fluid cognitive skills. Crystallized knowledge is all of the stuff you know — facts, math formulae, vocabulary, etc. Fluid cognitive skills are the ability to think quickly, keep things in memory, and solve new problems. The two are closely connected, but there are important distinctions between the two types.
West and his colleagues collected data from more than 1,300 8th graders in Boston, including some of the city’s famously high-performing charter schools to see how these schools affected both types of cognitive ability. The bottom line is that schools believed to be high-performing are dramatically improving students’ crystallized knowledge, as measured by standardized tests, but have basically no effect on fluid cognitive skills. That is, Boston’s successful charter schools appear to be able to get students to know more stuff but do not improve their ability to think quickly, keep things in memory, or solve new problems.
Perhaps we should be happy with the test score gains and untroubled by the lack of improvement in fluid cognitive skills. Chetty et al suggest that test score gains are predictive of later success in life, so who cares about those other skills? Maybe. But maybe the students in Chetty experienced improvements in both crystallized knowledge and fluid skills, but he only has measures of the former. It could still be the case that both types were essential for success.
There are worrisome signs that graduates from schools like KIPP are struggling in college despite impressive test score improvement in K-12. Perhaps the mis-match between improved crystallized knowledge and stagnant fluid skills cannot produce sustained success. Perhaps these products of successful ed reform know more of the high school curriculum but are unable to do things, like think quickly and solve new problems, that are important for later life accomplishment. E.D Hirsch and his followers have been convinced that gains in crystallized knowledge would translate into improved fluid skills, but that appears not to be the case — at least not in these model charter schools in Boston.
If fluid skills really matter, ed reform is in a serious pickle. First, we almost exclusively measure crystallized knowledge with our reliance on standardized tests. If anything, we appear to be increasingly emphasizing (and measuring) crystallized knowledge to the exclusion of fluid skills. So even when we manage to produce test score gains, we are more likely to neglect fluid skills.
Second, no one really knows how to improve fluid skills in a school setting. There are some laboratory experiments that have successfully altered fluid skills, but those effects are often fleeting and have never been replicated in a school environment. It’s taken us decades to devise some effective strategies for improving test scores. It may take us decades more to devise strategies for schools to affect fluid skills, even if we start caring about and measuring those outcomes.
Educational success probably requires addressing student needs and abilities on multiple dimensions. Large, technocratic systems built around standardized test results have a hard time focusing on more than the one dimension of test scores. The research by West, et al suggests that not all dimensions of academic progress necessarily move in sync. The unattended dimension of fluid skills may spoil the progress on the attended dimension of crystallized knowledge by undermining later-life success.
– Jay P. Greene