Manipulation checks are often overlooked in political science experiments despite their value. This article introduces factual manipulation checks (FMCs) as an effective method to assess individual-level attentiveness.

New insights emerge from four replication studies that show FMC placement has minimal impact on treatment effects and passage rates remain stable even after outcomes are revealed.

Unlike traditional approaches, FMCs uniquely identify distinct attentive patterns separate from instructional manipulation checks (IMCs). This distinction allows researchers to better understand participant engagement with experimental stimuli.

FMCs offer a practical solution for enhancing methodological rigor in political science research.