Among all the skills that distinguish an inquiry classroom from a conventional one, how a teacher asks questions is the most visible — and the most often overlooked in teacher training. We're accustomed to asking questions we already know the answers to. Inquiry demands something different: questioning that opens up thinking space rather than closing it down.

Wilen (1987), in his foundational work on questioning techniques for teachers, distinguished between two types of questions according to their effect: convergent questions (which direct all thinking toward a single answer) and divergent questions (which open up many possible answers). In everyday teaching, these are better known as closed and open questions. In an inquiry classroom, both have a role — but the proportion needs to be reversed from what typically happens.

The Anatomy of Two Question Types

Convergent vs Divergent Questions: Effect on Students' Thinking Space ❌ Convergent Questions Many students 1 answer Example: "What is the boiling point of water?" ✓ Divergent Questions 1 question Many lines of thought Example: "What factors affect the boiling point?"
Figure 1. How convergent and divergent questions affect thinking space in the classroom. Divergent questions open up possibilities rather than closing them down.

Seven Questioning Techniques That Change Classroom Dynamics

1
Wait time: productive silence
After asking a question, wait at least 3–5 seconds before calling on anyone or answering yourself. Rowe (1986) found that when teachers extended wait time from an average of 0.9 seconds to 3 seconds or more, students' answers became 300–700% longer and the number of students who participated rose significantly. Silence is not emptiness — it's thinking in progress.
Count silently to 5 after you ask. It feels like a long time, but the results are real.
2
Probing: digging deeper without judging
When a student answers, don't immediately judge it as right or wrong. Ask deeper: "Can you explain why you think that?" or "What led you to that conclusion?" Do this for correct and incorrect answers alike, so students can't tell whether they're being "tested" or "engaged in dialogue".
Physics: A student says, "Heavy objects fall faster" → ask, "What have you seen that makes you sure? How could we test it?"
3
Redirecting: pass it to the class, not back to the teacher
When students ask you something, resist the impulse to answer directly. Redirect the question to the class: "Who can help answer X?" or, better still, "How could we find out?" This shifts the locus of authority from the teacher to the learning community.
Student: "Sir, why doesn't oil mix with water?" → Teacher: "Good question. Does anyone have a hypothesis? How could we test it?"
4
Hypothetical questions: "what if...?"
Hypothetical questions invite students to think counterfactually — one of the most rarely practised higher-order cognitive skills. "What if gravity on Earth were twice as strong?" or "What if all the plants in this ecosystem suddenly disappeared?" There's no single correct answer, but the process is scientifically rich.
Biology: "What if photosynthesis needs red and blue light, but this greenhouse only has yellow lamps?"
5
Evidence questions: "how do you know?"
This is the most important question in an inquiry-based science classroom: "What's your evidence?" Ask it consistently — for correct answers, incorrect answers, and even your own statements in front of the class. This habit builds a classroom culture where claims without evidence are not accepted, regardless of who makes them.
"You say this solution is acidic. How could you prove it other than with litmus paper?"
6
Think-Pair-Share: a structure for difficult questions
For questions that demand deep thinking, don't ask for immediate individual answers. Give students 1–2 minutes to think alone (Think), then discuss with a neighbour (Pair), and only then share with the class (Share). This improves the quality of answers and ensures all students are engaged — not just the fastest.
Chemistry: "Why do you think this reaction is endothermic? Think on your own for 60 seconds, then discuss it with your neighbour."
7
Reflective questions: closing by opening up
End each session not with a teacher summary, but with a question that invites students to reflect on their own learning: "What surprised you most today?" or "What questions do you still have after this lesson?" The last question is the most powerful, because it connects today's lesson to curiosity that students take home with them.
"Write down one question you're taking home from today's lesson. Not to answer now — just to think about."
⚠️ A Word of Caution

Changing the way you ask questions is one of the hardest things to do in teaching, because it means changing habits built up over decades. Start with just one technique, such as wait time, and apply it consistently for two weeks before adding another.

💬 Key Takeaway

The quality of student thinking in an inquiry classroom depends heavily on the quality of teacher questions. A good question is not the hardest one to answer — it's the hardest one to stop thinking about.