To make a science explainer video for class, pick one concept, decide which of four shapes it has (a process, a cycle, a comparison, or a change of scale), and write a script of 300 to 600 words that follows that shape one step per paragraph. Paste the script into a document-first tool like openCanviz, keep your wording if you wrote it carefully, and it drafts a two to four minute narrated video with a drawing that builds as each step is explained. Then check every label on every drawing against your textbook. A generated science drawing is usually right about the shape of things and occasionally wrong about what they are called, and in a science class the name is the mark.

One concept per video

The most common reason a class explainer runs long and loses the viewer is that it tries to cover a topic instead of a concept. "Cells" is a topic. "How a cell makes energy from glucose" is a concept. "The cell cycle" is a concept. "Cells" is a term's worth of lessons.

A concept fits in two to four minutes. That is also roughly the length teachers ask for, and the length a classmate will actually watch.

The four shapes

Almost every concept in school science has one of four shapes. Naming the shape first tells you how to order the script and what the drawing needs to show.

If a concept seems to fit two shapes, pick the one your question is about. "Explain the water cycle" is a cycle. "Compare evaporation and transpiration" is a comparison, even though both happen inside the water cycle.

Write the script

A science explainer does not need a clever opening. It needs the concept stated in one sentence at the start, so the viewer knows what every step is building towards.

Open with the one-sentence answer. "Photosynthesis is how plants turn light, water and carbon dioxide into glucose and oxygen."

One step per paragraph. Each paragraph becomes one scene, and each scene gets its own drawing. A paragraph that holds three steps gets one crowded drawing.

Name each thing the first time it appears, and use the same name every time after. If it is the "chloroplast" in paragraph two, it is not "the green part" in paragraph four. Changing the word makes the drawing change too.

Say where things happen. "In the thylakoid membrane" gives the drawing somewhere to put the step. A step with no location is drawn floating in space.

End with one consequence or application. Why it matters, or what goes wrong when it fails. This is the part teachers most often say is missing.

At 150 words a minute, a 450-word script is a three-minute video. Write to the length you were given, not beyond it.

Make it

1. 1

   State the concept in one sentence

   If you cannot, the concept is too big. Split it into two videos.

2. 2

   Name the shape

   Process, cycle, comparison or change of scale. Order the paragraphs to match.

3. 3

   Write one paragraph per step

   Name the parts, say where each step happens, and keep each term the same throughout.

4. 4

   Paste it in and keep your wording

   Choose Keep my wording so the narration is exactly the script you checked. Pick a style: whiteboard for a class video, where the drawing builds as the point is made.

5. 5

   Check every label

   Pause on each scene and compare every label with your textbook's diagram. Fix any that are wrong in the editor.

6. 6

   Watch it with the sound off

   If the drawings alone tell the story in the right order, the video works. If one scene means nothing without the narration, redraw it.

The label check

This is the step that matters most and gets skipped most often.

A generated drawing of a plant cell will almost always look like a plant cell. What goes wrong is smaller and more expensive: a label pointing at the wrong structure, an arrow drawn the wrong way round, a stage of mitosis in the wrong order, a chemical formula with the wrong subscript. Any of these can cost the marks the video was supposed to earn.

Check four things on every scene.

Every label names the thing it points at. Compare with the diagram in your textbook, not from memory.

Every arrow points the right way. Energy flows, water moves, electrons travel. Direction is the most common error in drawn science.

Every formula and number is exact. Subscripts, charges, units and decimal points.

The order of the scenes matches the order of the process. Especially for anything with named stages, like mitosis or the stages of the heart cycle.

Anything wrong can be fixed scene by scene in the editor. You do not have to regenerate the whole video.

Whose work it is

A class explainer is usually assessed on whether you understand the concept, and the script is where that understanding shows. Write the script yourself, then use a tool to draw and narrate it. That keeps the thinking yours, which is also what most academic honesty policies ask for. Check your school's rules on AI tools before you hand it in, and say in your submission which tools you used if they ask. There is more on this in how to make a video for a school project.

What it costs

New accounts start with one hundred credits, which is roughly ten minutes of video, so a three-minute class explainer costs nothing to make. Free videos carry a watermark. For something you are handing in, a one-off payment unlocks that single project permanently, with no subscription, so you can re-export after you fix a label.

Common questions

Can I narrate it in my own voice? Some teachers ask for this, so check before you start. If your own voice is required, the drafted video still gives you a timed, scene-by-scene script to read from and a set of drawings to present over. If it is not required, a generated voice reading your own script is usually fine, because the script is the assessed part.

What if my concept needs an equation? Keep equations short and say them in words as well as symbols. "Energy equals mass times the speed of light squared." A viewer can follow a spoken equation. A long derivation belongs on paper.

How many scenes should a three-minute video have? Usually six to nine. One per step, plus an opening and a closing scene.

Is whiteboard style better than cartoon for science? For most science, yes. A whiteboard drawing looks like a textbook diagram being drawn, which is what a science explanation is. Cartoon style works for younger classes and for concepts with a character in them, like a red blood cell's journey around the body.