Learn

Learning preferences

Make learning more comfortable. Changes apply immediately.

Enlarges page content, including diagrams and their labels. You can also use your browser’s zoom.

Choose the colours that are easiest for you to distinguish. Applies to lesson diagrams and lab plots. Labels, shapes, hatching and line patterns also distinguish meanings. Source photographs and raw image brightness stay unchanged; mask-only views are available for image overlays.

ExampleComparisonSample link

Saved in this browser on this device. Preferences are separate from progress backups.

Learn through experiments

Twenty headlines, one observation

How much new evidence does a repost add?

Entering midway? Revisit Match a claim to its original record for the preceding worked example, or start here and use the explanation below.

1 · Try

Start with a concrete question

An original fictional report counts working water fountains. Reposts repeat it; separately authored inspections observe fountains on later days. No live sources or truth scores are used. The count choice applies only when at least one additional inspection exists.

Try the initial inputs, then write a prediction before changing one setting. All calculations run locally on your CPU.

Go directly to the experiment · Review basic mathematics

2 · Predict

What do you expect?

Predict whether adding ten reposts changes the number of underlying observations.

3 · Experiment

Change one thing. Inspect what happens.

  1. Add reposts and compare published items with underlying observations.
  2. Add independent inspections and read their dates.
  3. Introduce a conflicting count; propose two explanations other than dishonesty.
  4. Sketch the citation chain and write the next verification step.
Experiment inputs
Inputs
Your settingsMechanism
Calculation belowEvidence
Compare outcomes
Published items8 items
Distinct underlying observations2 observations
Contradictory observations0 observations

Compare the current results

Every bar starts at zero and uses the same numeric scale in this chart. The upper bound automatically adjusts to the largest current value (at least 1), so compare the numbers when changing inputs. Units and quantities come from each label; different kinds of quantity are not interchangeable. Displayed values are rounded to at most six significant digits.
06
  • Repeated items citing original6
    Repeated items citing original: 6Horizontal bar from zero to 6, on the shared zero to 6 numeric axis.
  • Distinct underlying observations2
    Distinct underlying observations: 2Horizontal bar from zero to 2, on the shared zero to 6 numeric axis.

Follow the calculation

  1. Original report O1: author counted 12 working water fountains on Monday.
  2. 6 reposts all cite O1; they add no new inspection.
  3. Independent inspection O2: 12 working fountains on Tuesday; a new observation at a different time.
  4. A differing count may reflect timing, definitions, or error. Inspect the underlying records before deciding.

Count provenance chains, not just headlines. More independent observations do not automatically settle a claim, and disagreement is a reason to investigate.

Captures keep your inputs, prediction and observation. Results are recalculated from those inputs. Resetting inputs keeps your captures and challenge history.

4 · Understand

Explain the mechanism

Twenty headlines, one observation

An original fictional report counts working water fountains. Reposts repeat it; separately authored inspections observe fountains on later days. No live sources or truth scores are used. The count choice applies only when at least one additional inspection exists.

Follow the mechanism

Six reposts plus an original are seven publications but only one underlying inspection. Repetition does not create a new measurement.

Independent inspections add observations, but different dates can mean they measure changed conditions.

A provenance map tells you where a claim came from. It cannot decide source truth automatically; inspect methods, definitions and timing.

Worked example

Original report O1: author counted 12 working water fountains on Monday.

6 reposts all cite O1; they add no new inspection.

Independent inspection O2: 12 working fountains on Tuesday; a new observation at a different time.

A differing count may reflect timing, definitions, or error. Inspect the underlying records before deciding.

Calculation

Published items = 1 original + reposts + additional inspections; distinct observations = 1 + additional inspections.

Try a controlled comparison

  1. Add reposts and compare published items with underlying observations.

  2. Add independent inspections and read their dates.

  3. Introduce a conflicting count; propose two explanations other than dishonesty.

  4. Sketch the citation chain and write the next verification step.

What this does not establish

  • All reports and inspections are original fictional teaching examples.

  • Independence is specified by the fixture, not inferred from real sites. Observation counts are not probabilities of truth.

5 · Apply

Try a fresh case

Nine articles repeat one report, and three more articles each describe a separate inspection. Including the original report, how many distinct observations are represented?

This is a public practice check. Retries support learning; matching a number does not certify independent proficiency.

Take the investigation further

Choose any extension. These are project prompts for you to carry out; they are not automatically assessed.

School investigation

Trace a harmless factual claim through its citations and note missing dates.

College investigation

Build an evidence table distinguishing primary observations from secondary summaries.

Workplace investigation

Create a verification memo that records provenance, contradictory evidence and unresolved questions.

6 · Continue

Keep the evidence, choose your next step

Completion records your own decision that you have worked through this investigation. Practice checks and independent project evidence are separate.