The example derives six possible pairs for A and two for B under V1. Both receive six picture cards, but B has only L1 and L2. V2 supplies both roles with all labels and recomputes capacity six each. The page separates that maximum from a manually entered hypothetical count; it reports no real participant performance or measure of effort.
Disclose the task and materials
Use six original matches: C1 cup/L1 cup, C2 key/L2 key, C3 leaf/L3 leaf, C4 book/L4 book, C5 pencil/L5 pencil, C6 star/L6 star. Both roles get C1 through C6, identical directions, and a proposed two-minute window. One matching label is required per complete pair. V1 prohibits label creation and trading. A gets L1 through L6; B gets L1 and L2. Explain the conditions before participation rather than surprising learners with an unannounced restriction after they begin.
Count matches by ID, not by loose objects on a desk. A can match all six cards; B can match C1 and C2. B lacks L3 through L6 for the remaining cards. The page computes this set intersection and identifies the missing labels. A maximum is not a guarantee that someone finishes within two minutes. Even a learner who understands all six pictures cannot complete the other four pairs from B's declared packet under the no-creation/no-trading rule.
Leave actual work separate
Keep condition version, declared label IDs, possible pairs and maximum alongside a separate actual-attempt record. That record needs materials actually supplied, completed pair IDs, timing, participation route, and notes. Blank means unrecorded, not zero or the resource maximum. If actual materials differ, record the change before interpreting a completion count. The example allows a hypothetical B count for discussion and rejects whole-number counts above the declared capacity as an inconsistency needing review, rather than treating them as valid observations.
Use packet roles, not personal income or identity labels. The teacher can offer untimed paper trace analysis or a pass under the participation plan. No family disclosure or public ranking is needed to analyze the rule. Record any actual assignment method separately, and do not call it random without a chosen random procedure. The teacher should focus feedback on the stated materials and evidence, not infer who worked harder, who deserved more, or what a learner's result says about personal merit.
Change the condition openly
V2 supplies both roles with L1 through L6 while keeping cards, instructions, and proposed window the same. Each capacity becomes six. Retain V1 as history rather than correcting it into the new condition. The page clears its hypothetical observation when the version changes, so an old count cannot masquerade as a fresh attempt. Actual worksheets should preserve each attempt under its own version. Repeating a task can involve practice, order and participation differences; this is not automatically a controlled causal experiment.
Debrief the rule connecting labels to possible pairs. Ask what changes if trading or creating labels is allowed, which count is a calculated bound, and whether any actual observations exist. Equalizing this resource does not establish equal performance or universal fairness. The small fictional model supplies no real-world wealth statistics or policy recommendation. Ask learners to name the available IDs and limiting rule, then distinguish the possible pairs from the pairs someone actually completed.
Make your own working example
Build an original resource-matching comparison with C1 cup, C2 key, C3 leaf, C4 book, C5 pencil, C6 star and matching L1-L6. Both roles receive all six cards, the same instructions and proposed two-minute window. Each pair needs its matching label; no creation or trading. V1 gives A all labels and B L1/L2. V2 gives both all six.
Provide V1,V2,Reset buttons. Compute possible pair IDs and missing label IDs by set membership. Show A6/B2 capacity for V1 and A6/B6 for V2, never as actual learner scores. Add a labeled hypothetical B count field and Compare button. Blank means unrecorded; negative, fractional and above-capacity counts need useful feedback. A valid practice count is not an actual classroom observation.
Version changes recalculate capacities and clear the hypothetical count; Reset restores V1 with blank observation. Keep actual materials, completed IDs, timing and notes outside the demo. Show the label rule and pair bank next to the result. Avoid personal-income roles, rankings, public disclosures, measured outcomes, real-world statistics, or a random-assignment claim.
Use one self-contained HTML file with no remote dependency. Keep the initial sample, output, and labeled controls near the top. Use at least 16px text, strong contrast, visible focus, and a stacked layout at 360px without horizontal overflow. Use explicit type=button click handlers and explicit DOM selectors; do not depend on native form submission. Clear stale feedback when task inputs change. Render entered text safely. Keep practice data local to the current page; do not imply saving, sending, or production integration. Return only the finished HTML.
Explain the constraint in the next handout
Retain actual attempts on versioned activity sheets. In an HTML comparison, NOS lets you revise eligible static explanatory text visually without AI regeneration. Clarify the no-trading rule so the next group can trace the capacity bound before discussing anyone's work.