lesson
Follow a question at each branch
1 · Learn
A classification key uses choices based on observable features to narrow an identification. Read each question carefully and follow the matching branch.
For a small set containing an ant, a spider and a snail: 'Does it have legs?' sends the snail to no. On yes, 'Does it have six legs?' sends the ant to yes and the spider to no. This key works for this stated set, not every animal.
2 · Worked example
I trace the spider through legs: yes; six legs: no. The remaining item in this three-item set is spider.
3 · Your turn
What route identifies the ant? If we add a woodlouse, does the old key still uniquely identify everything?
Check your answer
Yes to legs, then yes to six legs. No: a woodlouse would follow the not-six-legs branch with the spider, so more questions are needed.
4 · Apply your learning
Build and test a key for four accurate picture cards. Test every item and revise any ambiguous question.
Adult guidance and safety
Use photographs rather than capturing animals. Count visible features using suitable clear views.
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My observation notebook
With an adult, look at a safe real example or a checked photograph. Name the example and say which you used. Record what you actually notice. Do not taste plants or materials, approach unknown animals or invent missing observations.
Ask your teacher for support with the method and recording. A prediction is what you think might happen; an observation is what you actually see, hear or feel safely.
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Your records on this page
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