1. Introduction
The increasing digitalization of education has reshaped how instructors engage in professional development, particularly in transnational higher education (TNHE), where teaching and course preparation often involve cross-border collaboration. In this context, instructors work with geographically distributed colleagues, shared platform ecosystems, and differing institutional expectations, which increases the demand for professional learning that is flexible, scalable, and immediately applicable to daily teaching practice. Consequently, online continuing professional development (CPD) has become a prevalent mode of in-service teacher training, offering structured opportunities that can be adapted to instructors’ needs, goals, and teaching contexts [
1,
2,
3].
Online CPD typically integrates synchronous and asynchronous modalities—such as training modules, webinars, virtual workshops, and collaborative tasks—enabling instructors to engage with content, apply new ideas, and reflect with peers over time [
4]. For TNHE instructors, online CPD is not only convenient but also functionally important: it can reduce the constraints created by technological disparities, distributed teacher locations, and varied instructional expectations across international boundaries, thereby supporting coordination and professional learning across institutions [
5].
Technological Pedagogical Content Knowledge (TPACK) provides a widely used framework for understanding technology integration in teaching [
6]. It emphasizes the interaction among technology, pedagogy, and content knowledge, suggesting that effective digital teaching depends on coordinated development across these domains [
7]. This framework is particularly relevant to language teachers, whose work often centers on interaction design, scaffolding, collaborative learning, and iterative feedback rather than simple content transmission. In digital language teaching, technology functions not merely as a delivery tool, but as a medium for communication, drafting, feedback, and assessment. TPACK therefore provides a useful lens for understanding whether instructors can align technological tools with pedagogical purposes and language-learning goals. This relevance has also been recognized in prior language education research. Studies in language teaching and EFL contexts have used TPACK to examine teachers’ technology integration, develop context-sensitive assessment, and support professional learning for technology-enhanced instruction [
8,
9,
10,
11]. However, evidence remains limited on how routine online CPD supports TPACK development specifically in TNHE language teaching, where instructors work across institutional boundaries, shared platforms, and distributed teaching teams. It also remains unclear whether existing TPACK measures can adequately capture this kind of development in cross-border online teaching settings. Although online CPD is often designed to strengthen technology-integrated instruction, empirical evidence on whether and how routine online CPD supports TPACK development remains limited, particularly in TNHE language teaching contexts.
To address this gap, the present study conceptualizes transnational online CPD as a professional learning system in which program design features shape instructors’ TPACK through identifiable learning processes. Compared with domestic CPD, TNHE CPD requires instructors to negotiate shared teaching standards, platform practices, and pedagogical expectations with colleagues across institutional and national boundaries [
12]. In the present study, the online CPD program combined synchronous webinars and workshops with asynchronous LMS-based activities over an extended cycle. Core activities included platform-oriented training, collaborative lesson and task design, online assessment and feedback practice, peer exchange, and structured reflection on teaching artifacts. We therefore propose a feature–process–outcome framework: (a) these CPD features provide repeated opportunities to enact technology-integrated teaching; (b) they activate learning processes such as technology appropriation, pedagogical reasoning, collaborative problem solving, and boundary-crossing negotiation; and (c) these processes are expected to support short-cycle development particularly in TK, PK, and the integrative construct of TPACK.
To investigate how transnational online CPD supports TNHE language instructors’ TPACK development, a context-sensitive way of assessing teachers’ knowledge is first required. Because existing TPACK instruments were largely developed for other teaching environments, the present study adapts an established TPACK-EFL instrument to reflect the realities of online, cross-border language instruction. In this study, instrument adaptation and validation serve as a necessary methodological step for examining CPD-related development, rather than as the primary aim of the research. Accordingly, the study addresses the following questions:
RQ1: Does the adapted TPACK instrument provide an acceptable four-factor measurement model (TK, PK, CK, and TPACK) for assessing TNHE language instructors in online CPD contexts?
RQ2: To what extent do TK, PK, and CK predict instructors’ TPACK in TNHE online CPD contexts?
RQ3: Do instructors’ TK, PK, CK, and TPACK change from pre- to post-CPD participation?
5. Conclusions and Limitations
This study examined language instructors’ TPACK development in TNHE in the context of a routine online CPD program, and we tested an adapted TPACK self-report instrument designed for this setting. Validation relied on a split-sample strategy. The analyses supported a four-factor model (TK, CK, PK, and TPACK). Both EFA and CFA provided convergent evidence that the 23-item scale performs adequately in TNHE online teaching, with good model fit and acceptable internal consistency. The domains were moderately associated, which suggests that they move together conceptually but are still distinguishable as separate constructs, in line with TPACK’s multidimensional view of integration knowledge.
The study also goes beyond instrument validation by showing which domains matter most in TNHE online teaching. In the SEM, PK and TK both predicted TPACK, with PK emerging as the strongest predictor, while CK did not have a significant direct effect. The implication is that, within routine online CPD for language instructors, perceived integration competence is driven more by pedagogical design and technology fluency than by content expertise alone [
50]. At the same time, the absence of a direct CK effect does not mean CK is irrelevant. CK may work through other domains, or it may simply change too slowly to be detected over a short CPD cycle among experienced teachers. Future research should therefore test mediated pathways (for example, CK influencing TPACK through PK) and explore whether the CK–TPACK link varies by course type or by instructors’ roles.
The longitudinal part of the study provides direct evidence of change over time. Based on matched pre–post data, instructors reported higher TK, PK, and TPACK after the CPD program, while CK remained stable. Longitudinal invariance testing further supported at least metric invariance, which means the construct structure and the item loadings were broadly consistent across the two measurement points. Taken together, these results suggest that routine online CPD may be particularly effective for strengthening instructors’ technology-related and pedagogical capacities, which in turn support growth in the integrative construct of TPACK [
51]. In contrast, CK may require longer-term, content-focused professional learning structures or different indicators to detect meaningful change.
These findings have practical implications for CPD design and evaluation in TNHE language education. First, CPD initiatives may yield stronger impact when they are organized around pedagogical problems of practice (e.g., online interaction design, scaffolding, formative assessment, and feedback workflows) and demonstrate how specific digital tools serve those pedagogical intentions, rather than focusing on isolated tool training. Second, because TK and PK appear both predictive of TPACK and responsive to change over the CPD interval, they can serve as useful short-term indicators for monitoring CPD effectiveness in TNHE settings. Third, the validated four-factor instrument can support diagnostic use by TNHE administrators and teacher educators: it can help identify instructors’ strengths and gaps across domains, guide differentiated support and evaluate whether CPD activities are improving targeted competencies.
Several limitations should be acknowledged. First, the study relies on self-report measures, which may reflect changes in confidence or perceived competence rather than enacted teaching practice. Future studies should triangulate survey evidence with external indicators such as teaching artifacts, observation protocols, peer review, learning analytics, or student learning outcomes. Second, EFA, CFA/SEM, and the pre–post analysis were conducted on different subsamples, and the matched longitudinal sample was smaller due to attrition. Although this approach follows standard scale validation practice, future research should report institutional composition more explicitly and, where possible, use fully matched longitudinal panels for structural modeling. Third, while configural and metric invariance were supported, scalar invariance was not examined here; therefore, mean-change results should be interpreted cautiously. Future work should test scalar (or partial scalar) invariance and conduct latent mean comparisons to strengthen inference about change over time. Finally, the sample was drawn from TNHE partner institutions in China and from a specific CPD model, which may limit generalizability to other TNHE contexts.
Overall, this study contributes an empirically supported measurement framework for assessing TPACK in TNHE language instruction, clarifies the relative roles of PK and TK as predictors of integrative competence, and provides longitudinal evidence that routine online CPD is associated with growth in instructors’ TK, PK, and TPACK. These findings can inform the design of more targeted, pedagogy-driven CPD interventions and support more rigorous evaluation of teacher development in transnational digital learning environments.