Online diagnostic quiz for prior knowledge: five questions before a new unit

An online diagnostic quiz for prior knowledge answers a question you need before teaching a new unit: where should the first lesson begin? It is not a mini final exam. If students have not yet met the target concept, asking them to perform it mainly tells you that they have not been taught it. A useful diagnostic checks the knowledge and habits on which the next lesson depends.

This guide shows five questions for the start of a science unit on food webs, with a simple way to turn answers into teaching decisions. The questions are examples rather than a ready-made test for every age group. Adjust vocabulary and reading load to your students, then test each answer yourself. The method works equally well for a paper quiz if devices are unavailable.

Map the prerequisites before writing items

Suppose the upcoming unit asks students to reason about what happens when one species in a food web declines. They will need to identify producers and consumers, understand that arrows represent transfers of energy and distinguish evidence from a guess. Those are the prerequisites. The full complexity of ecosystem change is the new learning target, so do not expect a complete causal explanation yet.

Write down the action you will take for each possible gap. If most students reverse the arrow direction, start with a visual explanation. If they identify producers correctly but struggle to justify a claim, model how to cite an observation. If only a few students need support, plan a short small-group check while the rest move to the next task. The quiz becomes a planning tool only when these actions are plausible.

The Education Endowment Foundation’s feedback evidence stresses that information about learning is useful when it helps close the gap between current and desired understanding. A total score is therefore less informative than seeing which prerequisite is missing. This is the same principle behind formative assessment that works, applied before the unit starts.

Five questions for a food-web unit

Provide a small, clearly labelled diagram with grass, rabbit, fox and a second plant eater. Review the biology and arrow convention used in your curriculum before sharing. The questions below cover distinct signals rather than five ways to recall the same definition.

Question	Evidence it reveals	Possible teaching move
“Which organism in this diagram is a producer? Why?”	Recognition of a producer and reasoning	Revisit how plants obtain energy if students choose an animal.
“Draw an arrow to show energy moving from grass to rabbit.”	Direction of an energy-transfer arrow	Model arrow direction with a physical example.
“A rabbit eats grass. Is it a producer or a consumer?”	Difference between the two roles	Compare how the rabbit and grass obtain energy.
“A student says the fox gives energy to the rabbit because the arrow points toward the fox. What is confused?”	Ability to explain a common diagram error	Discuss what each arrow means, not just where it points.
“What observation would help us know whether fewer rabbits affected the foxes?”	Difference between a claim and evidence	Model an observable change before introducing a causal story.

The first three can be partly closed questions, but still benefit from a short reason. The fourth and fifth are better as open responses because they reveal a thought process. If every item is reduced to a selected option, a student may guess correctly while keeping the wrong explanation. The guide to writing good multiple-choice questions helps make wrong options diagnostic when a closed format is appropriate.

Do not try to measure reading stamina, drawing skill and food-web reasoning all at once. A complex image or a long prompt can turn the diagnostic into a test of another ability. Keep the diagram simple and check that its labels remain legible on a phone or printed sheet.

Set a low-stakes contract with students

Tell students: “I am using these answers to plan our first lesson. This is not a grade.” That sentence gives them a reason to show uncertainty rather than hide it. Offer a “not sure yet” option when guessing would conceal a missing prerequisite. Leave enough time for a short explanation and avoid a public leaderboard. The purpose is to learn what the class needs, not to rank students before teaching begins.

You can deliver the questions through an online classroom quiz. Skolina lets students join through a link or QR code without making individual student accounts; the teacher decides what identifying information to ask for. Choose the minimum information needed for your objective. A class-level pattern may not require the same identity details as a follow-up for individual students. Keep a paper alternative for a student who cannot open the link. If you plan to use this across several classes, review the Skolina pricing options before setting up your routine.

If you generate a question draft with AI, inspect both the answer key and the diagram. AI can phrase a plausible but biologically wrong arrow explanation. It may also introduce a species absent from the image. Use the draft as a starting point and confirm each item against the material you will actually teach. The Institute of Education Sciences practice guide connects questions with retrieval and explanatory feedback; a wrong key would undermine both.

Read answers by prerequisite and change the first lesson

After the quiz, look at the distribution for each question. Imagine most students choose grass as the producer, but half draw the energy arrow backward. A mean of four correct out of five could look reassuring. It misses the exact obstacle that will make tomorrow’s food-web discussion confusing. Start with arrow meaning, then check again using a different pair of organisms.

Use a three-part review:

1. Shared gap: a prerequisite many students miss becomes a short whole-class explanation and a new example.
2. Small-group gap: a few students need targeted practice while others begin the core task.
3. Question problem: if an item is ambiguous, revise it before treating the answers as evidence of understanding.

Open responses deserve a few minutes of human reading. An automatic score can mark a clear closed answer, but it cannot reliably distinguish every explanation of an arrow. Read a sample of justifications and look for recurring phrases. If students write “the fox gives energy to the rabbit,” show a counterexample and ask them to explain the new arrow in their own words.

This diagnostic belongs before the new unit. For a check at the end of a lesson, use our exit ticket questions for teachers instead. Both can be short, but they answer different planning questions: where to begin and what to do next.

A small plan for tomorrow

Before the class leaves, write one sentence: “Because question 2 showed reversed arrows, I will begin with a grass-to-rabbit model, then ask students to label a second example.” That is a more useful outcome than a spreadsheet of scores without action. Save a good question for the next cohort and rewrite any item students misunderstood because of its wording.

If you want to run this diagnostic before your next unit, create five reviewed questions, share a low-stakes link and read the patterns by prerequisite. Create a Skolina teacher account and start with the decision you need to make, rather than the number of questions you can generate.