Informal Digital Learning of English (IDLE) as Form‐Focused and Meaning‐Focused Activities: Refining its Measurement and Examining its Predictive Role in L2 Achievement and Confidence

Acknowledging the limitations of existing measurement instruments in adequately capturing the distinct cognitive processes (e.g., form‐focused vs. meaning‐focused) involved in informal digital learning of English (IDLE), this paper asserts a pressing need to develop and validate robust instruments that measure form‐focused and meaning‐focused IDLE (FM‐IDLE). It comprises two interrelated studies investigating the measurement and impact of informal digital English learning practices among Chinese university students. Study 1 aimed to develop and validate a psychometrically sound instrument to assess learners’ participation in form‐focused IDLE Activities (FIA) and meaning‐focused IDLE activities (MIA). Study 2 examined the predictive relationship between FIA, MIA, and two critical language learning outcomes: L2 achievement as indicated by students’ standardized English test scores and L2 confidence. The research engaged 1,202 Chinese undergraduate EFL learners, with the sample randomly divided into two datasets (Sample 1: N = 601; Sample 2: N = 601) for scale validation, while the complete sample ( N = 1202) was utilized to examine the scale's predictive validity. Study 1 yielded a refined 14‐item FM‐IDLE Scale comprising two distinct factors, FIA and MIA, demonstrating robust psychometric properties. Study 2, employing structural equation modeling, revealed differential effects: FIA demonstrated significant and negative associations with L2 achievement and L2 confidence, whereas MIA could positively predict these outcomes. These findings yield important pedagogical implications by highlighting the importance of promoting meaning‐focused IDLE activities through technological affordances while fostering language learning confidence against the backdrop of the global spread of English.