I have explained often about the essential flaw with grade-level proficiency, notably the third-grade reading myth.

Grade level in reading is a calculation that serves textbook companies and testing, but fulfills almost no genuine purpose in the real world; it is a technocratic cog in the efficiency machine.

Now that we are squarely in the newest reading war, the “science of reading,” two other aspects of grade-level proficiency have been central to that movement—the hyper-focus on third-grade reading proficiency that includes high-stakes elements such as grade retention and the misinformation rhetoric that claims 65% of students are not reading at grade-level (the NAEP proficiency myth).

These alone are enough to set aside or at least be skeptical about rhetoric, practice, and policy grounded in grade-level proficiency, but there is even more to consider.

A Twitter thread examines grade-level achievement aggregated by month of birth:

The thread builds off a blog post: Age-Related Expectations? by James Pembroke.

The most fascinating aspect of this analysis thread is the series of charts provided:

As the analysis shows, student achievement is strongly correlated with birth month, which calls into question how well standardized testing serves high-stakes practices and how often standardized testing reflects something other than actual learning.

Being older in your assigned grade level is not an aspect of merit, and being older in your assigned grade seems to have measured achievement benefits that aren’t essentially unfair to younger members of a grade.

Further, this sort of analysis helps contribute to concerns raised about grade retention, which necessarily removes students most likely to score low on testing and reintroduces those students as older than their peers in the assigned grade, which would seem to insure their test data corrupts both sets of measurements.

This data above are from the UK, but a similar analysis by month/year of birth applied to retained students and their younger peers would be a powerful contribution to understanding how grade retention likely inflates test data while continuing to be harmful to the students retained (and not actually raising achievement).

There appears to be even more problems with grade-level proficiency than noted previously, and now, even more reason not to continue to use the rhetoric or the metric.