Interview vs. Observation Tradeoff
The BLS tested whether interview-based data collection and direct job observation would produce similar measurements for occupational requirements. Field economists observed workers for 60-minute periods and compared results to interview data.
The test revealed a fundamental tradeoff:
Interviews capture requirements as understood by respondents, what they believe the job needs. This aggregates across workers, tasks, and time periods. It’s efficient at scale but filtered through interpretation.
Observation captures requirements as enacted, what workers actually do during a specific window. It’s grounded in behavior but limited to observable activities and short time samples.
Neither method is definitively superior. Interview data may miss requirements respondents take for granted or underweight rare-but-critical demands. Observation data may over-weight whatever happened during the observation period.
The BLS ultimately uses interviews for production collection, accepting the interpretation filter in exchange for scalability and coverage of non-observable requirements (cognitive demands, credential requirements).