Portland Arthur Academy Charter School vs Riverdale Grade School

Portland Arthur Academy Charter School and Riverdale Grade School sit 6.3 miles apart in Portland, Oregon, and their overall ratings are nearly identical — 9.2/10 versus 9.1/10, a gap of just 0.1 points. In Oregon's statewide rankings, Portland Arthur Academy Charter School lands at #37 of 1,226 schools, while Riverdale Grade School follows at #51 of 1,226. Both schools sit comfortably in the state's top 5 percent, meaning the choice between them turns on specific priorities rather than a clear quality gap.

Academically, the two schools diverge in opposite directions. Riverdale Grade School scores a 9.9/10 on the academic proficiency measure — 0.6 points higher than Portland Arthur Academy Charter School's 9.3/10. That delta signals a meaningful gap in current tested achievement levels. Portland Arthur Academy Charter School, however, leads on the growth score: 9.0/10 versus Riverdale Grade School's 8.6/10. Growth scores capture how much students improve relative to academic peers with similar starting points, which means students at Portland Arthur Academy Charter School are advancing at a faster rate even if their absolute proficiency ceiling sits lower.

On demographics, the schools differ substantially in scale. Riverdale Grade School enrolls 400 students — more than twice the 164 enrolled at Portland Arthur Academy Charter School. Student-teacher ratios are close (Portland Arthur Academy Charter School at 16.4:1, Riverdale Grade School at 16.0:1), so class sizes track similarly despite the enrollment difference. Portland Arthur Academy Charter School operates as a charter school, which typically means an application or lottery process and a distinct instructional model, while Riverdale Grade School is a regular public school serving its attendance zone.

The grade range is the sharpest structural difference: Portland Arthur Academy Charter School serves grades KG–05, so families will face a middle school transition after fifth grade. Riverdale Grade School extends through grade 8, keeping students in one building through middle school and reducing the number of school transitions a family manages before high school.