This study attempted to conceptualise and measure learners' perceptions of their collaborative problem-based learning and peer assessment strategies in a technology-enabled context. Drawing on the extant literature, we integrate collaborative, problem-based and peer assessment learning strategies and propose a new model, the collaborative problem-based learning and peer assessment (Co-PBLa-PA) conceptual framework, which forms the basis of a new psychometrically sound and conceptually based scale, the collaborative problem-based learning and peer assessment strategies inventory (CO-PBLaPA-SI). The development and validation of the CO-PBLa-PA-SI, based on the methodological and conceptual insights gained from prior research, involved identifying the following four scales: capacity to collaborate, readiness to engage, task-based interest and peer feedback usefulness. An item pool comprising of 16 items was established and verified by two panels of judges using a formalised card sorting procedure. Confirmatory factor analysis was conducted to validate the instrument of a small-scale (N = 164) study. The CO-PBLa-PA-SI scale showed strong construct validity and reliability with a Cronbach's coefficient alpha ranging from 0.828 to 0.880, which suggested strong internal consistency. The resultant instrument is intended as a tool to reliably measure learners' perceptions of their collaborative problem-based learning and peer assessment strategies in a technology-enabled context.