Researchers across academic disciplines have applied Instructional Manipulation Checks (IMCs) to detect inattentive survey participants (Anduiza & Galais, 2017; Motta, Callaghan, & Smith, 2016; Oppenheimer, Meyvis, & Davidenko, 2009; Paas & Morren, 2018; Peer, Brandimarte, Samat, & Acquisti, 2017; Persson & Solevid, 2013; Van Vaerenbergh & Thomas, 2013). IMCs typically instruct participants to endorse a specific category, such as “strongly agree,” or to skip answering the question altogether. Inattention is detected when the respondent fails to follow these instructions.IMC-failers have been found to have different values on marketing variables such as attitudes toward advertisements and brands (Paas & Morren, 2018). IMC-failers can also reduce the magnitude of negative correlations between oppositely scored scale-items (Paas, Dolnicar, & Karlsson, 2018), their responses can reduce test power (Berinsky, Margolis, & Sances, 2014; Oppenheimer et al., 2009) and their response patterns may obscure analyses and manipulations (Maniaci & Rogge, 2014). Their inattention therefore has important implications for survey researchers. Full paper available at https://doi.org/10.1093/ijpor/edz046