LET’S TRY ONE
Report A records 400 library visits during one week, counting each entry. Report B records 260 different visitors that week, counting each person once even if they returned.
Which difference explains why the numbers need not conflict?
One counts entries, while the other counts distinct people.
Returning visitors can produce multiple entries but only one distinct-person count.
Learning steps & teaching tips
Resolve apparent discrepancies by identifying differences in definitions, denominators or measurement intervals.
- Identify the quantity or statement each report actually defines.
- Compare inclusion rules, denominators and starting points before comparing values.
- Explain whether both statements can be true under their stated definitions.
Try it together
Write two truthful descriptions of one small dataset using different measures. Explain the distinction a reader must keep.
Before declaring two reports contradictory, compare what each number counts, the denominator, the time interval and the definition used.