“…Axelsson & Wilder, 2014; Hostyn, Daelman, Janssen, & Maes, 2010), a common practice is to use and/or adapt instruments developed for other target groups. The frequent use of instruments originally aimed at young typically developing children (Chadwick, Buell, & Goldbart, 2019; Hostyn, Petry, Lambrechts, & Maes, 2011; Van keer et al., 2017; Vandesande, Bosmans, Schuengel, et al, 2019) is based on the assumption of comparable levels of functioning and developmental trajectories. However, due to the complex interplay between the cognitive, motor and/or sensory impairments of persons with PIMD, this comparability cannot be guaranteed and the person may be at risk of being underestimated (Houwen, Visser, van der Putten, & Vlaskamp, 2016; Visser, Vlaskamp, Emde, Ruiter, & Timmerman, 2017).…”