The Dual-Investment Framework: Understanding Identity Positioning, Fidelity, and Effectiveness in the Case of a Non-Native English-Speaking Reading Interventionist

Most English language teachers globally are non-native English speakers (NNESTs), yet research studying their professional identity and teaching effectiveness remains limited. This study introduces the Dual-Investment Framework (DIF), which posits that instructional support and NNESTs’ agentic efforts work together to promote positive internal and external identity positioning, high instructional fidelity, and instructional effectiveness. The study examined how instructional support and agentic efforts related to the interventionist’s professional identity positioning, implementation fidelity, and student reading and writing outcomes. Instructional support consisted of structured coaching and curricular resources, and agentic efforts were documented using teacher diaries. Autoethnographic analysis of the NNEST’s teaching diaries, supplemented by teacher and parent surveys and news media coverage, documented the interplay between instructional support and agentic efforts in the NNEST’s internal and external positioning, including the development of internal confidence, relational legitimacy with families, and professional legitimacy with school stakeholders. Fidelity ratings exceeded 90% in most evaluated sessions. Quantitative findings demonstrated strong effects on letter–sound knowledge (Tau-U = 0.94) and moderate-to-strong effects on word- and text-level reading and writing outcomes (Tau-U = 0.80–1.00). We propose that the DIF, by integrating instructional support with agentic efforts, may promote effective literacy instruction while fostering positive professional identity positioning.