Misconceptions inventory
An evidence-based catalogue of common pupil misconceptions across school subjects. Each entry includes the misconception, the correct understanding, diagnostic items teachers can use in class, and corrective approaches grounded in the research.
Maths
2- Place value and decimal comparisonKS2KS3
0.45 is bigger than 0.5 because it has more digits
“0.45 is bigger than 0.5 because it has more digits. The longer the number, the larger it is.”
Decimal numbers are compared by place value, not length. Each column after the decimal point is worth a tenth, a hundredth, a thousandth. 0.5 is five tenths; 0.45 is four tenths and five hundredths. Five tenths is more than four tenths, so 0.5 is bigger.
Open entry → - Multiplication and division with rational numbersKS2KS3
Multiplication makes a number bigger
“When you multiply two numbers, the answer is always bigger than both. When you divide, the answer is always smaller.”
Multiplying by a number less than 1 makes the result smaller. Dividing by a number less than 1 makes the result bigger. The intuitive rule comes from whole-number examples and does not generalise.
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Science
3- Evolution by natural selectionKS3KS4KS5
Evolution has a goal or purpose
“Organisms develop new features because they need them. Evolution has a direction and moves towards more advanced or more complex organisms, with humans at the top.”
Natural selection has no goal and no foresight. Random variation in offspring produces individuals that differ slightly. Those that survive and reproduce in the current environment pass on their traits. There is no "more advanced", no end-point, and no purpose, just differential survival and reproduction.
Open entry → - Forces, gravity and free fallKS3KS4KS5
Heavier objects fall faster than lighter ones
“A heavier object falls faster than a lighter object when dropped from the same height.”
In the absence of air resistance, all objects fall at the same rate, called the acceleration due to gravity (around 9.8 metres per second squared at the Earth's surface). The mass of the object does not change this rate, because the larger gravitational force on the heavier object is exactly balanced by its larger inertia.
Open entry → - Plant nutrition and photosynthesisKS2KS3
Plants get their food from the soil
“Plants take in food from the soil through their roots. Soil is their food.”
Plants make their own food (glucose) in their leaves, from carbon dioxide and water, using energy from sunlight. Soil supplies water and a small number of mineral nutrients, not food.
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How we build this
Each entry is grounded in published research. We cite the studies that document the misconception, the corrective approaches, and the diagnostic items where they exist. Entries are reviewed against the evidence at least once a year, and the review date is shown at the bottom of every page.
We treat this inventory as a living catalogue. If you have published research, a diagnostic item bank, or classroom data that should be included, get in touch.