A pilot study is a [ ] of a planned investigation, carried out [ ].
A pilot study is a formal peer review of a planned investigation, carried out during the main study.
A pilot study is a final data analysis of a planned investigation, carried out after data collection.
A pilot study is a small-scale trial run of a planned investigation, carried out before the main study.
A pilot study is a full-scale replication of a planned investigation, carried out after the main study.