Can’t Do Won’t Do Assessment (CDWD)

 

Skill Deficit or Motivation Deficit?

Understanding the Root of Student Struggles:  The CDWD assessment

We all know that motivation plays a role in student performance.  But how do we determine if it is a factor for a particular student?  In classrooms across the country, educators work tirelessly to improve instruction, adjusting their methods and refining their strategies.  Yet research tells us that a significant share of student underperformance does not stem from an inability to learn but rather from a lack of motivation--the "won't-do" problem.  No matter how sound the instruction, if motivation is missing, the best teaching will falter.

Too often, we rely on casual observation to judge whether a student is struggling due to a lack of skill or simply a lack of will. This habit leads to incorrect assumptions and ineffective interventions. We need more than a guess; we need a way to know. The Can't Do/Won't Do (CDWD) assessment offers a structured, research-based method for distinguishing between these two barriers to learning, helping us respond with precision instead of speculation.

The CDWD assessment: A Tool for Clarity and Action

The CDWD assessment is a practical tool, designed not just to measure performance but to reveal what stands in the way of improvement. Research confirms that when students receive the right kind of support—whether focused on skill-building or motivation—their progress is substantial. But we must first diagnose the real problem.

The process is straightforward: A teacher begins with an assessment such as Oral Reading Fluency to establish a baseline. The student then selects a preferred reward from a "treasure chest" of age-appropriate incentives. They are told that surpassing their baseline score will earn them the reward. The task is re-administered, and their performance is observed. If the student improves markedly (usually more than 20%), they receive the reward; if they do not, a small consolation prize may be given.   Students who improve markedly may benefit from instruction combined with a motivation component.  This does not mean “reward” because often setting goals for the student and providing positive attention is sufficient. 

 

 

Intervention is a Great Assessment Tool

At first glance, this might seem less like an assessment and more like an intervention. And in truth, it is both. The CDWD assessment exemplifies what researchers call treatment validity—meaning that it not only identifies a problem but also provides the first step toward solving it. In other words, it doesn’t just measure; it teaches.

The CDWD assessment: An Important Part of Problem Identification

We recommend this assessment as part of perhaps the most import part of MTSS: Problem Identification.  Over and over research has shown that you can solve problems if you know what the problem is.  The CDWD assessment clarifies the problems after screening.  A student who is below level has one of two problems, they can’t do it or they won’t do it.

The CDWD directly tests which interventions work for each student. For those who struggle because of a won’t-do problem, incentive-based strategies prove most effective. For those struggling due to a can’t-do problem, additional instruction is needed. When assessment and intervention are closely linked, we move beyond speculation and into action, ensuring that every child receives the specific support they need to thrive.

In a time when education is too often reduced to broad measures and generic strategies, tools like the CDWD assessment remind us of something simple but essential: real progress comes from knowing the student, understanding the struggle, and responding with precision and care.

 

Why Conducting a “Can’t Do / Won’t Do” Assessment Matters

Within an MTSS framework, identifying why a student performs below expectations is just as important as determining that they are below expectations. Research consistently shows that roughly 70–80% of students who score low on academic screening measures have a genuine skill deficit (“can’t do”), while 20–30% perform poorly primarily because of motivation or task engagement (“won’t do”) (Daly, Martens, Hamler, Dool, & Eckert, 1999; Witt, Daly, & Martens, 2004).

Much of this evidence comes from studies using one-minute Curriculum-Based Measurement (CBM) assessments, which directly measure academic fluency and minimize fatigue and disengagement. Because these tasks are brief and transparent, they allow educators to observe both skill and motivational components of performance. In contrast, the influence of motivation on lengthy computer-adaptive tests—which may last 45–75 minutes—is largely unknown. For high-performing students, results from such long assessments may remain relatively stable, but for lower-performing students, who are more prone to frustration or fatigue, the results may be suspect and reflect motivation or task persistence as much as actual skill level.

Without distinguishing between “can’t do” and “won’t do,” schools risk implementing skill-based interventions for students who already possess the necessary skills but lack motivation. In those cases, weeks of instruction may yield little change—not because the intervention is ineffective, but because the problem was misdiagnosed.

A Can’t Do/Won’t Do (CDWD) assessment directly addresses this issue by briefly testing whether performance improves when incentives, modeling, or goal-setting are introduced. If the student’s performance increases immediately, it indicates a motivational problem that responds to reinforcement-based strategies. If not, the student likely needs explicit, targeted skill instruction.

The CDWD approach has treatment validity—its results accurately predict which type of intervention will be effective. In other words, it connects assessment directly to action, ensuring that instructional time and resources are used efficiently. Integrating a brief CDWD assessment into the MTSS problem-solving process allows educators to match students to the right support the first time, reducing trial-and-error and accelerating student progress.

Interested in Digging Deeper?

This article draws on research published by Dr. Joseph C. Witt and others in the field of MTSS and evidence-based interventions. You can browse more than 95 of Dr. Witt’s publications on ResearchGate and Google Scholar.

For readers interested in a full research study behind this summary, a complete article is available as a free PDF download on ResearchGate.

Educators seeking step-by-step guidance on MTSS assessment, CDWD administration, and data-driven intervention can explore the Can't Do/Won't Do Best Practices Chapter.