The "Accuracy Over History" Principle

Traditional averaging treats a student's initial struggle with the same importance as their final mastery. Research from Ken O'Connor argues that this approach is fundamentally inaccurate and results in grades that misrepresent what students have actually learned (O'Connor, 2011).

The Problem: A student who fails a pre-test but aces the final exam is objectively proficient, yet a traditional average might classify them as merely "average."
The 65/35 Solution: By weighting the recent attempt at 65%, the gradebook prioritizes validity (what the student knows now) over history (what they used to not know). This aligns with O'Connor's core principle that grades should reflect current achievement, not serve as a historical record of learning struggles.

The Power Law of Learning (Marzano)

Robert Marzano's research demonstrates that learning does not progress linearly—it accelerates as concepts click into place. His work on the "power law of practice" shows that performance improvement follows a predictable curve with rapid early gains followed by gradual refinement (Marzano, 2006).

The Research: Marzano introduced a "power law algorithm" for grading that gives greater weight to recent assessments when determining mastery. His research demonstrates that power-law models can predict a student's final performance more accurately than simple averaging (Marzano, 2006).
The 65/35 Connection: A 65% weight on the most recent evidence provides a curve that closely approximates Marzano's recommended weighted trend approach. It represents the most accessible way to apply complex statistical growth models within a daily gradebook.

The Psychological "Safety to Fail" (Guskey)

Thomas Guskey emphasizes that grading should support student learning and motivation rather than undermine it. His research challenges traditional percentage-based calculations that can create insurmountable mathematical barriers for students who struggle early (Guskey, 2015)

The Barrier: If a student receives a 0% early in a unit, it often becomes mathematically impossible to earn an "A" using a traditional mean—regardless of how hard they work or how much they ultimately learn.
The 65/35 Incentive: Because 65% of the score is tied to the current assessment, students always have a meaningful path to success. This calculation removes the "mathematical trap" and fosters what researchers describe as a growth-oriented approach to learning.

Comparison Matrix for Stakeholders

Stakeholder	Concern	The 65/35 Response
Teachers	"Does it reflect true growth?"	Yes. It acts as a weighted trendline that honors the student's most recent performance level, consistent with Marzano's power law research.
Students	"Can I recover from a bad start?"	Yes. The 65% weight means their latest effort is nearly twice as powerful as their past mistakes.
Parents	"Is this consistent and fair?"	It is fairer than a traditional average because it rewards learning progress rather than punishing the natural learning curve.
Admins	"Is this based on research?"	Yes. It is the practical application of Marzano's power law algorithm and O'Connor's guidelines for accurate grading.