The measure crops up frequently in discussions of education policies and, sometimes, products. But what the heck does it even mean?
Charter advocates like to point to a CREDO study that shows urban charters giving students an additional 40 days of learning growth in math and 38 in reading (while critics bring up the 2013 CREDO study finding that charter schools provided seven additional days of learning per year in reading and no significant difference in math). Indianapolis, New York City, and other big systems find charter advocates touting additional days of learning.
But what exactly is a day of learning? Classroom teachers know that a Monday is not equal to a Friday or a Wednesday. Surely it’s not the day that students get out early, or the day that is interrupted by an assembly, or the day that the teacher was pulled out for meetings, or the day that the baseball team was dismissed early for an away game. Certainly not the day that everyone in school was reeling and preoccupied because of a local tragedy. A day in September is not the same as a day in April, and certainly not any day in the season that we’re approaching, because from mid-November until the end-of-year break classroom teachers are extra-challenged to get a day out of a day.
So when is it? When does this proto-typical day, this day on which exactly one day’s worth of learning occurs? Where is education’s answer to Lebanon, Kansas (the geographic center of the contiguous U.S.)? Is it a statistical anomaly like the1.9 children being raised by the average U.S. family? Can this measure be broken down more precisely? Can we talk about hours of learning? Minutes? Seconds?
To create this benchmark, CREDO adopted the assumption put forth by Hanushek, Peterson, and Woessman (2012) that “[o]n most measures of student performance, student growth is typically about 1 full standard deviation on standardized tests between 4th and 8th grade, or about 25 percent of a standard deviation from one grade to the next.” Therefore, assuming an average school year includes 180 days of schooling, each day of schooling represents approximately 0.0013 standard deviations of student growth.
So in the end, “days of learning” has nothing to do with days or with learning. It’s simply another way to say “this policy or product seems to correlate with an increase or decrease of scores on a standardized test of reading and math.”
Learning can’t be measured in days or minutes or inches or pounds or hectares. Pretending that you can use test scores, assumptions and standard deviations to measure learning the same way you can portion out milk in a measuring cup is not science–it’s rhetorical smoke and mirrors.
If you wonder why classroom teachers are not more engaged with or moved by educational research, here’s one reason–because the euphemisms and constructs of researchers use a frame of reference totally removed from the experience of classroom teachers, designed to hide what they’re really talking about instead of illuminating it. Someone who approaches a classroom teacher and says, “I’ve got a way for you to get more days of learning out of your students,” should not expect to be taken seriously.