“…Although this area of CALL inquiry is still in its infancy, the current literature provides mixed results of IDLE for language learning. For example, Burston (2014Burston ( , 2015 and Sung, Chang, and Yang (2015) have reported that mobile language learning in informal settings produced limited effects. In contrast, other studies have suggested a positive relationship between IDLE and L2 outcomes such as speaking (Mitra, Tooley, Inamdar, & Dixon, 2003), writing (Sun et al, 2017), vocabulary (Jensen, 2017; Sundqvist & Wikstr€ om, 2015;Sylv en & Sundqvist, 2012), reading and listening (Sylv en & Sundqvist, 2012) and formal testing (Lai, Zhu, & Gong, 2015;Sundqvist & Wikstr€ om, 2015).…”