Concept structure choices are equivalent to case-selection decisions.

Evidence

The explicit choices researchers make about how to structure particular concepts are tantamount to decisions about which observations to select into an analysis. As such, particular concept structures carry the potential for selection biases. — Gary Goertz, Social Science Concepts, 1091

Categorization

• DEEPTHINKING: Quietly collapses the distinction between measurement and sampling: every definition of a concept is already a choice about which world you will see.
• XREF: Echoes Along the Archival Grain on how institutional categories determine which events get recorded at all.