<![CDATA[Being able to ask questions does not necessarily mean being able to formulate questions that can be investigated using empirical evidence. This study describes the development of investigable questioning skills through the Investigable Questioning Formulation Technique (IQFT) in fifth-grade integrated science and social studies lessons. A two-cycle classroom action research study involved 28 students at SD Negeri Mojoroto 3 during the first semester of the 2026/2027 academic year. Assessments were conducted at baseline, Cycle I, and Cycle II using an analytical rubric addressing relevance, clarity of focus, empirical testability, and feasibility. Students generated questions individually and selected their best question for assessment. The second cycle incorporated scaffolding through examples and non-examples of investigable questions. Data were analysed descriptively at class and individual levels. Mean scores increased from 59.23 to 75.89 and 88.69, while the proportion meeting the mastery threshold of 75 increased from 32.14% to 64.29% and 89.29%. All students obtained final scores above baseline, although three remained below the threshold. The target of at least 85% class mastery was achieved in Cycle II. IQFT implementation with refined instructional support was associated with positive classroom-level development. Interpretation is limited by the absence of a comparison group, different assessment stimuli, and assessment of only one student-selected question per stage.]]>
