Evidence-Based Assessments

Imagine attempting to calculate the structural integrity of a suspension bridge using a tape measure made of elastic. Every time you measure a steel beam, the tape stretches differently. One engineer reads twenty feet; another reads twenty-two. Even if you manage to write down a number, you have no idea if you are actually measuring the beam’s length or simply the elasticity of your tool.

In special education, we regularly make life-altering decisions for children—decisions regarding placement, instructional interventions, and legal rights. Making these decisions based on faulty, subjective instruments is the educational equivalent of building a bridge with elastic tape. The foundation of special education rests on our ability to look past assumptions and gather precise, actionable data. To do this, we must understand the physics of our measurement tools.