What Do Great Teachers Do When a Class Does Poorly on a Unit Exam?

by Michael Keany

August 16, 2026

Every teacher eventually experiences the unsettling moment when the results of a unit exam appear—and they are far worse than expected. Perhaps half the class failed. Maybe nearly everyone missed the same questions. The temptation is to blame the students: They didn’t study. They weren’t paying attention. They should have worked harder.

Great teachers resist that reaction.

Instead, they treat poor classwide performance as information. An assessment isn’t simply a device for assigning grades; it is evidence about what students learned—and potentially about what needs to happen next in instruction.

The central question becomes not “Why did they do so badly?” but “What do these results tell me about what I should do next?”

1. They Analyze the Errors Before Analyzing the Students

Great teachers don’t begin with the average score. They examine patterns.

Which questions did most students miss? Which standards weren’t mastered? Were mistakes conceptual or procedural? Did students understand the material but misinterpret the questions?

This distinction matters enormously. Research by Thomas Guskey and Laura Link found that teachers regarded analyses of student errors on formative assessments as particularly useful for planning corrective instruction and improving teaching. (Default⁠)

If 70 percent of students missed questions involving the same concept, that isn’t merely 20 individual students getting something wrong. It is a classroom-level instructional signal.

2. They Examine Their Own Instruction

Great teachers ask an uncomfortable but essential question:

“Is there something I could have taught differently?”

That doesn’t mean every poor result is the teacher’s fault. Students have responsibilities, too. But when an entire class struggles, effective teachers investigate whether the learning objective was clear, students had sufficient practice, formative checks identified misconceptions early enough, and the assessment actually matched what was taught.

The Education Endowment Foundation emphasizes that effective feedback rests on high-quality initial instruction and formative assessment that identifies learning gaps. (EEF⁠)

Great teachers accept responsibility without accepting blame.

3. They Reteach Differently

If students didn’t learn something the first time, simply repeating the original lesson louder and slower probably isn’t the answer.

Great teachers change the approach.

They might use visual representations, worked examples, manipulatives, peer explanations, small-group instruction, different texts, or additional guided practice.

Mastery-learning research emphasizes that corrective instruction should address identified learning difficulties and offer students another pathway toward understanding. (ASCD⁠)

The operative word is corrective. Reteaching should respond directly to what the assessment revealed.

4. They Involve Students in the Diagnosis

Students should participate in analyzing their own performance.

Instead of simply returning an exam marked “62,” the teacher might ask students to classify their mistakes:

I didn’t know it.
I misunderstood the concept.
I made a careless error.
I misread the question.
I knew part of it but couldn’t apply it.

This transforms the test from a verdict into a learning tool.

Research on feedback indicates that feedback is most productive when it gives learners specific information that helps them move toward the learning goal. (EEF⁠)

5. They Provide Another Opportunity to Demonstrate Learning

After meaningful corrective instruction, great teachers ask an obvious question:

“Did they learn it now?”

That requires another assessment.

It doesn’t necessarily mean administering the identical exam. Students might complete a parallel assessment, solve new problems, revise written responses, or demonstrate mastery another way.

Guskey argues that assessments followed by corrective instruction and a second opportunity to demonstrate success can make assessment part of the learning process rather than simply its endpoint. (ASCD⁠)

6. They Don’t Lower the Standard

Reteaching is not giving students an easier test.

Neither is reassessment “giving away grades.”

The learning target remains the same. What changes are the time, instruction, feedback, and opportunities students receive to reach it.

That’s an important distinction.

Great teachers maintain high expectations while recognizing that students don’t always reach those expectations on the same timetable.

The Test Should Change Something

Perhaps the simplest principle is this:

If an assessment reveals that most students haven’t learned something important, something should happen because of that information.

Great teachers don’t record the grades, move to Chapter 7, and tell students to study harder next time.

They diagnose. They reflect. They reteach. They provide corrective feedback. And then they check again.

Because the ultimate purpose of a unit exam shouldn’t merely be to determine who learned.

It should also help teachers determine what to do about those who haven’t learned—yet.

References

1. Guskey, T. R. (2003). “How Classroom Assessments Improve Learning.” Educational Leadership, 60(5). Association for Supervision and Curriculum Development. (ASCD⁠)
2. Guskey, T. R., & Link, L. J. (2022). “Feedback for Teachers: What Evidence Do Teachers Find Most Useful?” AASA Journal of Scholarship and Practice, 18(4), 9–20. (UKnowledge⁠)
3. Education Endowment Foundation. (2021). Teacher Feedback to Improve Pupil Learning: Guidance Report. Education Endowment Foundation. (EEF⁠)

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Prepared with the assistance of AI software

OpenAI. (2026). ChatGPT (5.2) [Large language model]. https://chat.openai.com