Learn Choose honest denominators and assemble evidence for a concise recommendation.
Start with everyday situations, predict an outcome, and test your ideas. You need basic arithmetic, percentages and graph reading; explanations introduce additional ideas where needed. No coding or account is required. Every investigation has school, college and workplace extensions—you can choose any of them.
Create a clear instruction, honest chart specification, research paragraph and decision proposal with traceable evidence.
Open any topic directly. Review functions and graphs whenever useful.
The original two-investigation starter remains available. Choosing the full course adds its published lessons to your selected scope; your earlier work stays saved. Skipping does not count as completion or understanding.
Free exploration: no completion scope selected yet. Project reports and independent evidence are tracked separately.
Choose a unit, then open a lesson on its own page. This outline lists the sequence; it does not combine the full lessons into one page.
Repair consequential ambiguity and name the population behind a percentage.
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Which revision removes consequential ambiguity?
Two authored reader interpretations expose ambiguous actors, checks and deadlines. Write your own repaired draft in your investigation notes.
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Which people does a percentage actually describe?
Original fictional survey: invitees may respond, and respondents may report satisfaction. Nonresponse is unknown. Sliders retain requested counts. The model caps actual responses at invitations and actual satisfied respondents at actual responses; metrics, bars and traces use those actual counts.
Select relevant evidence within space constraints and specify a chart without misleading geometry.
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Which evidence fits the decision and the available space?
Original fictional pilot: completion records, four interviews and timing observations describe different aspects of a product. Evidence bundles have explicit assumed word costs including context.
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How does an axis floor change the apparent size of a difference?
Two observed quantities, 92 and 96, can be encoded as bars or points. Inspect geometry, then specify or sketch your own chart.
Separate observation from causal claims and defend a recommendation against explicit constraints.
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Can group composition explain a reported tool advantage?
Authored cohort comparison: experienced participants finish all tasks and new participants finish half. Tools have no causal effect in this fixture.
○ Not marked complete · Included · Practice check available
When does a faster process violate the service requirement?
Compare fictional service plans with setup time, per-case work and explicitly assumed unresolved-case rates.
Prepare a before/after instruction, a claim-to-evidence table, a chart specification or attached chart, and a concise proposal about a fictional service. Preserve the original draft so a reviewer can inspect your revision decisions.
Save a report, compare captured evidence, and attempt three new cases. A completed report records submitted work; the rubric supports a separate human review of its quality.
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