Definition
Diagnostic questions are carefully designed prompts that focus on common misconceptions or tricky ideas. They uncover how students are thinking and provide insights into misunderstandings, partial knowledge or reasoning errors.
When used in formative assessment, diagnostic questions:
- reveal the specific nature of misconceptions, not just whether an answer is wrong
- can include multiple plausible options (including common errors as distractors) or open-ended prompts that capture students’ reasoning
- give teachers a quick snapshot of class understanding to help adapt instruction in the moment
- prompt students to reflect on why an answer is correct or incorrect, building awareness of their own thinking.
Design considerations
When designing diagnostic questions, use the identified formative focus to consider:
- what content, concepts or processes are likely to cause confusion or common errors
- whether the questions include options or prompts that surface misconceptions and partial understandings, rather than just test for correct answers.
For you and your students, consider:
- whether the wording is clear, unambiguous and accessible so misunderstandings revealed are about the concept, not the question itself
- what scaffolds will clarify your expectations, and ensure all students can access and respond to the task
- what digital tools could expedite collecting, analysing and responding to learning evidence.
Aim
Diagnostic questions help assess students’ ability to:
- understand an idea or concept, or how or why a process works
- explain their thinking or connect ideas
- plan, choose, use or adjust strategies when they solve problems or respond to challenges.
Timing
Diagnostic questions are helpful:
- before teaching to check prior learning or uncover misconceptions
- during the lesson to check student learning and guide teacher response in real time.
Evidence
Students demonstrate their learning by selecting right or wrong responses, or constructing short or extended responses.
In the classroom
These examples show how assessment with diagnostic questions can be used to check for misconceptions, gaps in understanding and errors in reasoning.
- “Agree or disagree?” questions: students decide whether statements are true or false, valid or invalid, and explain their reasoning, revealing progress and uncovering misconceptions.
- Error identification tasks: students diagnose mistakes in worked examples or processes and explain corrections, demonstrating conceptual clarity.
- Misconception-based choices: students choose from options designed to reflect common misunderstandings, helping surface reasoning errors.
- Quick quizzes with justification prompts: students respond to targeted questions and reflect on their reasoning, surfacing errors and partial understandings.
- Sorting tasks: students classify examples into categories and explain their thinking, making reasoning visible.
- “Which is correct?” questions: students evaluate 2 solutions or explanations and justify their selection, revealing depth of understanding.
