Öztürk, MesutSarikaya, İsmailAlbayrak, Mustafa2026-09-012026-09-0120262602-4829https://doi.org/10.5152/hayef.2026.26001https://search.trdizin.gov.tr/tr/yayin/detay/1434771https://hdl.handle.net/20.500.12403/8412While research on metacognition in mathematics education has grown recently, it has primarily focused on problem- solving, with little attention given to problem-posing. However, problem-posing also involves complex metacognitive processes that warrant deeper investigation. This study addresses this gap by developing and validating a new instrument to assess metacognition in problem-posing among middle school students. The metacognition in problem-posing Scale is an eight-item measure encompassing three factors: planning, monitoring, and evaluation. The study was conducted using a scale-development design within a survey research framework, and data were collected through a two-stage simple random sampling. Psychometric analyses confirmed the scale’s reliability and its construct validity. The metacognition in problem-posing Scale offers a promising tool for exploring students’ metacognitive engagement in problem-posing tasks and has potential applications in both research and classroom settings.eninfo:eu-repo/semantics/openAccessEğitimEğitim AraştırmalarıArticle11610.5152/hayef.2026.260011434771