Assessing Scientific Thinking in Early Childhood: Development and Validation of the Scientific Thinking Skills Assessment Tool (STS-AT)

This study reports the development and validation of the Scientific Thinking Skills Assessment Tool (STS-AT), designed to measure scientific thinking in children aged 5–8 years. The STS-AT assesses four domains: critical inquiry, hypothesis testing, analytical interpretation, and metacognitive awareness. Item development was guided by theoretical frameworks and expert review, followed by pilot testing with 72 children, which demonstrated clarity and inter-rater reliability (Cohen’s κ = 0.88). The final instrument comprised 12 open-ended tasks supported with visual aids and scored on a four-point rubric. The main study involved 282 children from Turkish kindergartens and primary schools. Reliability analyses indicated strong internal consistency (Cronbach’s α = .87) and high test–retest stability (r = .91). Exploratory and confirmatory factor analyses supported a four-factor structure with excellent fit (RMSEA = .04, CFI = .95, TLI = .93, SRMR = .06). Results showed significant improvements in scientific thinking with age (F(3,278) = 18.81, p < .001, η² = 0.17), while no gender differences were observed (t = -1.01, p = 0.315). These findings suggest that the STS-AT is a valid, reliable, and developmentally appropriate tool for assessing scientific thinking in early childhood.