Phase III: Content Validation
We invited 7 external experts representing diverse disciplines, including health informatics, public health, medicine, sociology, social work, and measurements. The panel of multidisciplinary experts agreed to participate in content validation, and all of them were remunerated for their time. Each expert was asked to evaluate the preliminary item pool based on 3 criteria: relevance (the extent to which the items aligned with the definition of digital literacy across the 5 domains), clarity (the clarity and conciseness of the items), and comprehensiveness (whether the items adequately covered all 5 domains of digital literacy). Relevance and clarity were assessed using a 4-point Likert scale (1=very inappropriate, 2=inappropriate, 3=appropriate, and 4=very appropriate), while comprehensiveness was evaluated using open-ended questions to encourage suggestions.To examine the content validity, we used the item-level content validity index (I-CVI) and the scale’s content validity index (S-CVI) [