Unfortunately, comparing private to public school test scores is a bit like comparing apples to oranges.
Public schools use their own set of standardized tests, which they use for a variety of purposes: assessment and diagnostics, to name two. Private schools use a different set of tests - some derived from the same basic tests public schools use and created by the same companies - but still different enough that they can't be compared side by side with public school tests.
We hear over and over from parents who have left public school to attend St. Agatha that our curriculum is challenging compared to what their child was learning while enrolled in public school. Our Catholic high schools report that St. Agatha students consistently arrive well prepared for a rigorous high school curriculum, and our students often test into advanced classes.
According to a report by the National Catholic Education Association, Catholic school students are more likely to graduate and attend college than students attending other schools, public or private. The report touts a Catholic high school student graduation rate of 99.2 percent, higher than graduation rates of religious (97.5), non-sectarian (93.9) or public schools (84.1). Source: Broughman, S.P., Swain, N.L. (2013); Stillwell, R., and Sable, J. (2015).
“[Catholic high schools'] effectiveness in educating students, even from disadvantaged backgrounds, has been cited consistently in research published over the last 25 years,” said Marie A. Powell, executive director of the Secretariat of Catholic Education of the United States Conference of Catholic Bishops (USCCB). “The Catholic community can be very proud of their support for such schools.”
The report also states that Catholic school graduates are more likely to attend four-year colleges than students graduating from other religious and non-sectarian schools. Additionally, 86.5 percent of Catholic school graduates go on to attend four-year colleges while only 44 percent of public school graduates do.