To make a lab report video, keep the sections of a written report and give each its own scene or two: aim, hypothesis, variables, method, results, analysis, conclusion and evaluation. State the aim as one question, show the method as a labelled diagram rather than a paragraph, put your real results in a table and then a graph with units, and spend at least a quarter of the running time on analysis and evaluation, because that is where most of the marks are. Three to five minutes is usually enough. Never adjust, smooth or invent data to make the video look tidier. A drawn video explains your experiment; it is not evidence that you did it.

How a lab report video differs from other science videos

A science explainer teaches a concept that is already known. A science fair video argues for a project you designed yourself. A lab report video sits between them: you are reporting a set practical, often one every student in your class did, and the marker wants to see that you understood why each step was there and what your results do and do not show.

That changes where the effort goes. The method is usually given, so it needs to be clear, not original. The results are yours and will differ from your classmates'. And the evaluation, where you say what limited your data, is the section teachers say students rush. If you are entering a fair rather than reporting a class practical, how to make a video for a science fair project covers the judging side.

The sections, and what each one has to do

The percentages are a guide. The point is the shape: the opening is quick, the method is clear, and the second half of the video is about thinking.

Worked example: rates of reaction with sodium thiosulfate

This is the disappearing cross practical. In AQA GCSE Chemistry it is part of the required practical on how concentration affects rate, which asks for "a method involving a change in colour or turbidity", and versions of it appear in most school chemistry courses.

The chemistry: sodium thiosulfate solution reacts with dilute hydrochloric acid to give sodium chloride, sulfur dioxide, water and solid sulfur. The sulfur forms as a fine precipitate that makes the solution cloudy. A cross drawn on paper under the flask gradually disappears from view, and you time how long that takes. A shorter time means a faster reaction.

Na₂S₂O₃(aq) + 2HCl(aq) → 2NaCl(aq) + SO₂(g) + S(s) + H₂O(l)

The numbers in the scene list below are invented to show the format. Your video uses your own data, including the awkward bits.

Scene 1, the aim. "How does the concentration of sodium thiosulfate affect the rate of its reaction with hydrochloric acid?" On screen: a conical flask on a paper cross.

Scene 2, the hypothesis. "As the concentration of sodium thiosulfate increases, the time for the cross to disappear will decrease. In a more concentrated solution there are more particles in the same volume, so collisions with acid particles happen more often, and there are more successful collisions per second." On screen: two boxes, one with few particles and one with many, with collision marks.

Scene 3, the variables. "Independent: the concentration of sodium thiosulfate, set by diluting it with water. Dependent: the time for the cross to disappear. Controlled: the volume and concentration of acid, the total volume of solution, the temperature of the room, the same flask and the same cross." On screen: a three-column table, filling in as each is named.

Scene 4, the method. "I measured 50 cubic centimetres of sodium thiosulfate solution into a flask on the cross, added 10 cubic centimetres of hydrochloric acid, swirled once and started the timer. I stopped it when I could no longer see the cross from above. Then I repeated it with the thiosulfate diluted: 40 cubic centimetres with 10 of water, then 30 with 20, down to 10 with 40. Three runs at each concentration." On screen: a labelled diagram of the flask, the cross, the measuring cylinders and the eye looking down, with the dilution table beside it.

Scene 5, safety. "Sulfur dioxide is an irritant gas and can trigger asthma, so the room was ventilated and the flask emptied into the sink straight after each run, as the teacher instructed. Eye protection throughout." On screen: goggles and an open window.

Scene 6, raw results. "Here are all fifteen runs." On screen: a table with five rows of volume and three time columns and a mean. Read two rows aloud: "At 50 cubic centimetres, the mean was 21 seconds. At 10 cubic centimetres, 112 seconds."

Scene 7, the anomaly. "One run stands out. At 30 cubic centimetres, the second run took 58 seconds when the others took 40 and 42. I left it out of the mean and I will come back to why." On screen: the 58 circled, the mean recalculated from the other two.

Scene 8, the graph. "Plotting rate, which is one divided by the time, against volume of thiosulfate gives roughly a straight line through the origin." On screen: the axes drawn first, labelled, then the points one at a time, then the line of best fit.

Scene 9, the conclusion. "As the concentration increased, the time decreased and the rate increased. Rate was roughly proportional to concentration, which supports the hypothesis and matches collision theory." On screen: the hypothesis from scene 2, with a tick.

Scene 10, the evaluation. "The biggest problem is the end point. Deciding when the cross has gone is a judgement, and it changes with the light and with who is looking. That probably explains the anomaly: I think the second run at 30 was timed by my partner. Next time, the same person should judge every run, or a light sensor and data logger could measure the cloudiness instead." On screen: two eyes looking at the same flask with different verdicts, then a light sensor.

Scene 11, the summary. "Higher concentration, faster reaction, roughly in proportion. The weakest part of the method is the end point, and a sensor would fix it." On screen: the graph, small, with one line of text.

That is about 600 words of narration, close to four minutes.

Presenting the data honestly

The results scenes are where a video can mislead without anyone meaning to. Some rules that keep it straight:

• Show the raw data before the means. A marker wants to see that you did repeats and how much they varied. A table of means alone hides that.
• Keep the anomaly in. Circle it, say what you did with it, and explain it in the evaluation. Quietly dropping it is the one thing that looks like fiddling.
• Draw the axes before the points. Name each axis and its unit first, as in how to explain a graph in a video. The viewer reads the points correctly only if they know what the axes are.
• Plot rate when the theory is about rate. Time against concentration curves downward; one over time against concentration is close to a straight line. Say which you plotted and why.
• Use the same number of decimal places as your equipment. A stopwatch read by a human is good to about a second at best. Writing 21.37 seconds claims a precision you did not have.
• Check every number on every scene. Generated drawings round, swap and mislabel figures. Compare each value in the video with your results table, line by line.

If your results did not support the hypothesis, say so. A clear account of why is better science, and usually better marks, than a forced fit.

What the video cannot do

The drawn video is your report, not your evidence. Your teacher will still want the results table from the lesson, and some courses require a written report as well. Keep your raw data sheet and any photos of your setup. If the course allows it, a short phone clip of the real flask turning cloudy can be cut into the video with any basic editor, and it makes the results scene far more convincing than a drawing of one.

Do not draw equipment you did not use or steps you did not do. If you ran out of time and only did two repeats, the video says two.

Writing the narration

Use past tense for the method and present tense for the theory. "I added 10 cubic centimetres of acid." "More particles collide more often." Mixing them makes the method sound like a recipe and the theory sound like an anecdote.

Say units every time. "21 seconds", "50 cubic centimetres". A listener cannot see your table headings.

Name variables the same way throughout. If it is "concentration of sodium thiosulfate" in scene 3, it is not "strength" in scene 9.

Make the evaluation specific. "Human error" earns nothing. "Judging the end point by eye varied between people" earns the mark, and "a light sensor would remove the judgement" earns the next one.

For general advice on scripting science for the ear, including the label check for diagrams, see how to make a science explainer video for class.

Make it

1. 1

   Collect your real data first

   Raw results table with every repeat, the means, any anomaly marked, and the graph drawn in a spreadsheet or on paper with units on both axes.

2. 2

   Write one paragraph per section

   Aim, hypothesis, variables, method, safety, results, analysis, conclusion, evaluation. Give the evaluation at least as many words as the method.

3. 3

   Mark the numbers you will say aloud

   Two or three values from the results, the anomaly, and the overall pattern. These become the spoken lines in the results scenes.

4. 4

   Paste the script into openCanviz

   Set the target length and choose Keep my wording so your conclusion and evaluation are said exactly as you wrote them. Whiteboard style suits a lab report because diagrams and tables build line by line.

5. 5

   Check every figure and label

   Compare each number, unit, equation and piece of equipment on screen with your results sheet. Fix any wrong scene in the editor rather than regenerating the whole video.

6. 6

   Watch it as the marker would

   Once through with a timer. If the evaluation is shorter than the method, add one more specific limitation and its improvement.

Common questions

How long should a lab report video be? Three to five minutes for a school practical, or whatever your teacher sets. That is 450 to 750 words of narration. A first-year university practical with more analysis may need six or seven.

Can I use another group's data if mine went wrong? Only if your teacher allows it, and you must say so on screen. Better still, present your own data with an honest account of what went wrong. That is often marked well, because it shows you understand the method.

Should I narrate in my own voice? Check the brief. Where the content is what is assessed, a generated voice reading your script is usually fine. If your own voice is required, record it and replace the generated narration; the scenes stay the same.

Do I need to include the chemical equation? For a chemistry practical, yes, once, early, and said in words as well as symbols. Build it reactants first, then products, as described in how to explain an equation in a video.

What style looks right for a lab report? Whiteboard, which reads like a diagram being drawn in a lab book. Avoid styles that make equipment look decorative; the marker needs to recognise every piece of apparatus.