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Controls and Comparison Groups
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GMAT
VR.089 Controls and Comparison Groups
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A transit authority introduces contactless fare gates first at stations with the worst crowding and later finds shorter entry times. Which comparison would best address both selection and citywide trends?
A
The upgraded stations' entry times during the single most crowded prelaunch week, using the same measurement plan, eligibility criteria, endpoint coding, and follow-up interval.
B
The upgraded stations after a nearby construction project ended, with the same reporting procedure and observation length.
C
Stations with similarly severe prelaunch crowding and parallel entry-time trends that retained old gates, comparing changes at both groups over the same dates.
D
Contactless users compared with riders who paid cash, after applying identical inclusion, exclusion, endpoint-coding, and data-quality rules.
E
Upgraded central stations compared with lightly used suburban stops, with the same recorded covariates included in the analysis.
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