In Europe the words immigrants, Turks, and Muslims function interchangeably

Evidence

That said, the constructs used to establish discriminant validity may have been flawed because in Europe, certain terms—immigrants, Turks, and Muslims—seem to be interchangeable. — Ummul-Kiram Kathawalla, Fei Bi Chan, Quratulain Gulamhussein, Amy Riegelman, and Moin Syed, Conceptualization and Measurement of…, 547

Categorization

• STORYSTEM: Fiction spark: a survey researcher in Vienna slowly realizes her carefully designed discriminant-validity questionnaire is measuring nothing distinct because her respondents genuinely cannot tell the categories apart.
• XREF: Directly supports the racialization framework referenced in fn. 6 — prejudiced targets are collapsed by phenotype and stigma, not theology.