Counting what is easy to count
Holding the difference between a measurement and the thing it stands in for, across two texts that both blur it.
Paired texts
Text 1: A ten-year survey of a nature reserve recorded the number of bee species seen by volunteers each summer. The count rose from 41 species in the first year to 63 in the tenth. The reserve manager describes the rise as evidence that the habitat restoration is working.
Text 2: Over the same decade the number of volunteers taking part rose from 12 to 48, and in 2019 the reserve began running identification workshops. Species counts of this kind record what observers notice and can name, not what is present.
Answers in order, explanations withheld, and a report on where the chain broke.
- 31.1Central ideas and detailsStandard
What did the survey in Text 1 record?
- AThe number of bee species that volunteers saw and identified.
- BThe total number of bees living in the reserve.
- CThe number of bee species present in the reserve.
- DThe area of habitat restored each year.
Show the answer and reasoningHide the reasoning
The number of bee species that volunteers saw and identified.
Text 1 says volunteers recorded species seen. Text 2 makes the same point explicitly. What was present and what was noticed are different quantities, and only the second was measured.
- 31.2Command of evidenceChallenge
Builds on: Question 1's identification of what was actually measured — observation, which depends on observers.
Which detail in Text 2 most directly weakens the manager's interpretation?
- AThe number of volunteers quadrupled over the same period.
- BThe reserve began running identification workshops in 2019.
- CThe survey ran for ten summers.
- DSpecies counts record what observers can name.
Show the answer and reasoningHide the reasoning
The number of volunteers quadrupled over the same period.
More observers find more species whether or not more are present, and the increase is large enough to account for the rise on its own. The workshops matter too but began late in the decade; the general statement about counts sets up the problem rather than being the evidence for it.
- 31.3InferencesChallenge
Builds on: Question 2, which established that an alternative explanation exists — the step this question asks you not to overshoot.
Taking both texts together, which conclusion is best supported?
- AThe rise in recorded species is consistent with better observation, with better habitat, or with both.
- BThe habitat restoration has had no effect on bee species.
- CVolunteer surveys should not be used to monitor wildlife.
- DThe reserve manager misrepresented the data deliberately.
Show the answer and reasoningHide the reasoning
The rise in recorded species is consistent with better observation, with better habitat, or with both.
Text 2 supplies an alternative explanation; it does not rule the first one out. Concluding that restoration had no effect overshoots in the opposite direction, and neither text condemns volunteer surveys or alleges bad faith.
- 31.4SynthesisChallenge
Builds on: The two competing explanations held open in question 3 — this asks what would distinguish them.
The reserve wants a measure that would separate the two explanations. Which addition would help most?
- ARecording the number of observer-hours alongside the species count each year.
- BExtending the survey for a further ten summers.
- CAsking volunteers to report how confident they felt in each identification.
- DPublishing the counts in a scientific journal.
Show the answer and reasoningHide the reasoning
Recording the number of observer-hours alongside the species count each year.
Species per observer-hour would rise only if more species were genuinely present, which is exactly the separation the reserve needs. More years of the same measure inherits the same ambiguity, and confidence ratings and publication change nothing about what is being counted.