More Teachers, Same SOLs

James Weigand raises the question whether the divisions with more teachers per student get better SOL pass rates.

To look at that question, I’ve prepared a juxtaposition of Table 19 and Table 1 from the 2016 Superintendent’s Annual Report with the pass rates from that year.

Table 19 gives us each division’s total “instructional positions,” defined by VDOE as “classroom teachers, guidance counselors, librarians, technology instructors, principals, and assistant principals.”  Table 1 gives the end of year enrollment (known in bureaucratese as average daily membership, ADM).

Here, to start, are the data for the reading tests.

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The red diamonds, from the left, are the peer cities Newport News, Hampton, and Norfolk.  The gold square is Richmond; the blue diamond, Lynchburg; the green diamond, Charles City. 

If we fool around with the fitted curve, we can get the R-squared up to 1.2%, which is to say that the SOL performance does not correlate with the number of teachers per kid.

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Here, then, are the data for the remaining subjects and the five-subject average, all with the linear curve fitted.

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The closest thing to a correlation is History & Social Science at 6%; all the correlations, such as they are, are negative: Pass rates decreasing with increasing numbers of teachers.

At the division level, 2016 SOL performance did not improve with increasing numbers of teachers per student.