Association for Public Policy Analysis & Management

The grading bias caused by handwriting quality has yet been recognized as a discrimination that causes unequal opportunities in education. Handwriting quality has biological foundations and naturally associates with gender, sinistrality, and several types of disabilities like ADHD, dyslexia, etc. This study also utilizes a unique data showing that poor handwriting associates with good math and creativity. This study finds that this bias explains about 20% of total variance and 15% of gender difference in writing score, and provides a channel to explain the test score disadvantage in sinistrality.

This bias has yet been estimated because content quality naturally correlates with handwriting quality, and handwriting is hard to quantify. This study utilizes a special rule of handwriting quality score in Nantong prefecture’s 9th grade reading exam to quantify handwriting quality (in China). This study randomly creates several handwritten versions for each one of 800 representative essays to break the natural tie between handwriting and content quality. This study also employs instrumental variable method to correct measurement error on the right-side variable and avoids the attenuation bias. The estimated bias is about 0.4-0.5 stand deviation, which means 1 point in handwriting(0-5) causes 2.2-2.7 points bias in content score(0-60).

Additional experiment designs break the mechanism of this bias quantitatively into statistical discrimination and taste discrimination, and separate taste discrimination into two cognitive biases (halo effect and cognitive fluency effect).

To reduce discrimination and miss-select talents, this study suggests that schools should implement typing in exams as early as possible, and developing an optical-character-recognition grading system is urgent. This experiment is the first one with clean separation of statistical discrimination and taste discrimination, and the first one to quantitatively estimate halo effect.