Introduction28 The ability to be attentive has been widely regarded as a major prerequisite in motor learning 29 (Wulf & Lewthwaite, 2016), whether in a sport (Moran, 2016) or an educational context 30 where physical activities are taught (Standage et al., 2005). However, sport participants can 31 experience difficulties in turning their attention on sport situation (Maldonado et al., 2019; 32 Moran, 2016). Less is known on how to optimize attention during a sport situation. To our 33 knowledge, in comparison to the flourishing literature in cognitive and clinical psychology on 34 attention, research evidences, especially on the measurement of attention during a sport 35 situation, are sparse. Researchers have analyzed attentional processes through three kinds of 36 measures (Calmels et al., 2004): (1) behavioral (e.g. time reaction; Posner, 1980), (2) 37 physiological (e.g. pupil dilatation; van der Wel & van Steenbergen, 2018), or (3) self-38 reported measurement (Calmels et al., 2004). These methods have been applied to laboratory 39 situations. However, behavioral and physiological measurement can hardly be implemented in 40 ecological situations such as a sport situation. Thus, the purpose of the present paper was to 41 develop and validate a self-reported scale, to measure attention during a sport situation.42 The concept of attention entails a variety of interconnected processes (Ocasio, 2010). At least 43 three distinct forms of attention have been identified: attentional vigilance, selective attention, 44 and executive attention (Ocasio, 2010). Based on these three forms, the concept of attention in 45 sport has been used loosely to express performer's concentration (Calmels et al., 2004).46 Concentration was defined as the ability to focus on one source of relevant information while 47 ignoring distracting stimuli as irrelevant information (Moran, 2016). Concentration has been 48 used as a relevant cognitive ability for purposes of optimizing learning in sport (e.g. Moran, 49 2016) and physical education (PE; e.g. Maldonado et al., 2019). In contrast, distraction was 50 defined as a diversion of attention from some intended targets (Moran, 2016). Distraction