Use concept attainment to plan an ordered Yes/No sequence, invite a hypothesis, and choose a case that helps learners revise it. This teacher-preparation example includes the complete card sequence, a modeled hypothesis, and a separate transfer check.
Plan the examples before revealing the target term
In Jennifer Gonzalez's explanation of concept attainment, learners examine labeled Yes and No examples before the teacher supplies the concept's name and definition. Further cases help test and refine the characteristics they propose.
The instructional work is in choosing that sequence. Prepare a checked target rule, examples that fit, contrasts that fail for a reason, and a later case that tests an incidental feature learners might include. Do not begin the learner-facing sequence with the definition you want them to infer.
This original geometry exercise uses ordinary, noncrossing flat shapes. Its teacher key is rectangle: a quadrilateral with four right angles. A square meets that rule. Check the definition and the angle information before using the cards with your class.
The article is teacher preparation. The example's target-name and key controls are available to any viewer; they are not secure teacher-only access. Keep the key out of the learners' initial display when conducting the actual activity.
Read the complete teaching sequence
| Card | Supplied shape information | Teacher label and purpose |
|---|---|---|
| A | Red, wide quadrilateral with four marked right angles. | Yes: initial positive case. |
| B | Red, slanted parallelogram with two 60° and two 120° angles. | No: color is shared with A, but the angles differ. |
| C | Red, tall quadrilateral with four marked right angles. | Yes: a different proportion still fits. |
| D | Blue, wide quadrilateral with four marked right angles. | Yes: challenges a rule that requires red. |
| E | Blue square with four equal sides and four marked right angles. | Yes: equal sides do not exclude it. |
| F | Blue oval with a curved boundary. | No: blue is not enough; it is not a four-sided figure with right angles. |
The drawings must agree with these stated attributes. Mark and label the right angles rather than expecting a learner to infer them from a rough picture. Color can be named in text, so the contrast does not depend on color perception alone.
Reveal the labeled cards in order, leaving earlier cases available for comparison. After A, B, and C, invite a tentative rule and ask which features in the cases support it. Keep learners' own wording separate from the example's authored model.
Use D to examine the color condition
Choose Read modeled hypothesis to see this possible statement:
“The Yes group contains red shapes with four right angles.”
That is an invented teaching hypothesis, not a recorded pupil response. It fits A–C. Reveal D, labeled Yes, and compare its blue color with its four right angles. The red condition cannot remain a requirement if the proposed rule is to account for all the supplied Yes cases.
A revised modeled rule is a quadrilateral with four right angles. Ask what changed and which case made the revision necessary. Learners can propose other wording; discuss whether it explains the cases rather than judging it by matching a saved sentence.
E supplies another useful contrast. A rule that requires two long and two short sides would exclude the square, although E has the defining right-angle property. F then prevents a revision that simply accepts all blue shapes.
Before class, you can review this sequence with a teaching colleague in your NOS workspace. Ask why D is more diagnostic here than another red Yes case. Clarify a static instruction such as “Guess the shape” to “Propose a rule that explains the Yes and No cases” with visual editing if needed. Changing the programmed case order or reveal behavior requires editing that behavior too.
Check a new case before ending the activity
The two transfer cards are:
- G: a tilted blue quadrilateral with four marked right angles and unequal adjacent side lengths. It is Yes; orientation does not remove its right angles.
- H: a blue rhombus with equal sides, two 60° angles, and two 120° angles. It is No; equal sides do not supply four right angles.
Ask learners to place G and H and explain the attribute that decides each placement before revealing the teacher key. The supplied facts matter more than the appearance of the drawing. A tilted rectangle should not become No just because it no longer sits flat on the page.
Use the explanations to decide whether you need another diagnostic case. If a learner includes an unnecessary feature, choose a case that tests that feature. If the rule is too broad, choose a contrast that shares the tempting feature while failing a defining one.
Copy a prompt for the complete sequence
Create one complete HTML concept-attainment teacher-review page.
Target concept and checked defining rule: [PASTE]
Ordered Yes/No cases with exact attributes and reasons: [PASTE]
Incidental feature to test and diagnostic next case: [PASTE]
Transfer cases, learner access needs and teacher key: [PASTE]
Keep target name/definition out of the initial learner-facing case
display. Reveal labeled cases in order while earlier cases stay
available. Let a learner retain a tentative rule without automatic
prose grading. Keep teacher-authored model and learner text separate.
Include this original teacher-preparation geometry exercise:
Target rectangle = ordinary noncrossing flat quadrilateral with
four right angles. A square is a rectangle under this definition.
A: red wide quadrilateral, four marked right angles, Yes.
B: red slanted parallelogram, angles 60/120/60/120 degrees, No.
C: red tall quadrilateral, four marked right angles, Yes.
D: blue wide quadrilateral, four marked right angles, Yes.
E: blue square, four equal sides/four marked right angles, Yes.
F: blue oval, curved boundary, No.
Authored modeled hypothesis after A–C: The Yes group contains
red shapes with four right angles. It is not a real learner response.
D's Yes label challenges red as necessary. Revised modeled rule:
quadrilateral with four right angles. E includes a square; F shows
color alone cannot define the group. Explain case-to-rule reasoning.
Transfer G: tilted blue quadrilateral, unequal adjacent sides and
four marked right angles, Yes; orientation does not change the rule.
Transfer H: blue rhombus, equal sides, angles 60/120/60/120 degrees,
No; equal sides do not establish four right angles.
Make original SVG/text cards with accurate stated geometry, angle
markers and text attributes. Never infer a right angle from pixels.
Provide Next labeled case, Read modeled hypothesis, Show target/key,
and Transfer cases. G/H prompts precede their key explanation.
Reveal/key controls are available to every viewer, not secure teacher
access. Preserve a separate learner-hypothesis area as cases reveal;
warn before resetting it. Do not claim actual learner performance,
learning gains, automatic interpretation scores or submitted work.
Keep full case text accessible and text at least 16px. Native labeled
controls, visible focus, readable cards at 360px without overflow.
Inline CSS/JavaScript only, no external assets, network or storage.
State typing is temporary. Return complete HTML and geometry checks
the teacher should perform before using the actual class cards.
Read the generated Yes/No sequence with the target key. Check that D actually varies color while retaining four right angles, the square stays Yes, and the tilted rectangle's angle markers remain correct. Then inspect the initial display for a target-name leak.
Choose the next contrast from the explanation
Keep the planned sequence available, but listen for the particular condition a learner proposes. D tests whether color is necessary; E tests whether equal sides are being excluded; G tests whether orientation has become part of the rule. Ask which feature decided the placement and which earlier case supports that explanation.
If the rule still excludes squares, return to E before revealing the target term. If orientation is the difficulty, use G and its right-angle labels. Choose the case that addresses the explanation you actually heard.