When addressing psychological constructs and their implications for professional understanding and practice in early childhood education, educational research relies on trustworthy findings and measurement instruments originating from psychological research. In line with the conference theme Knowing and Acting, this paper conceptualises psychometric validation not as a merely technical prerequisite, but as a core epistemic condition under which educational knowledge becomes empirically visible and, consequently, actionable. Tests and questionnaires actively shape knowledge claims about children’s characteristics in educational research and professional discourse; understanding how such instruments function under specific developmental, linguistic, and contextual conditions is therefore central to the generation of robust educational knowledge.

Against this epistemological background, the study builds on the psychological conceptualisation of sensory processing sensitivity (SPS; Aron & Aron, 1997; Greven et al., 2025; Pluess, 2015), commonly discussed in the literature through the notion of highly sensitive children. SPS captures individual differences in responsiveness to physical, social and emotional stimuli and has been empirically linked to children’s socio-emotional functioning and well-being (Lionetti, 2019), central concerns in early childhood education. Research further suggests more pronounced vulnerability under adverse circumstances, alongside greater benefits in supportive environments (Li et al., 2022; Slagt et al., 2018), highlighting the importance of valid, context-sensitive measurement as a prerequisite for meaningful educational knowledge.

As systematic studies of age-appropriate measurement instruments for SPS in preschool-aged children remain rare, empirically grounded knowledge on SPS is still limited. The Highly Sensitive Child Scale – Parent Report (HSC-PR; Pluess et al., 2018), one of the core measures of SPS, was originally designed for school-aged children and requires further systematic validation for children aged 3–6 years across languages and in large-scale samples; in particular, no validation is currently available for the German-language version. Moreover, empirical work has reported item-specific difficulties (Sperati et al., 2022), which may suggest that one original item formulation did not adequately reflect age-specific developmental characteristics of early childhood.

Building on this gap, the present study aims to systematically examine the psychometric properties of the HSC-PR in preschool-aged children. The study draws on a large parent sample of children aged 3–6 years recruited through the vast majority of kindergartens in the Autonomous Province of Bozen/Bolzano (South Tyrol), a multilingual region in Northern Italy. By analysing the German and Italian language versions within a shared regional and cultural context and common institutional frameworks, the study enables a stringent test of cross-language comparability. In multilingual European education systems, comparable and transferable evidence depends on measurement equivalence rather than on translation alone (Putnick & Bornstein, 2016).

The study is guided by three interconnected research questions: (1) To what extent does the HSC-PR demonstrate satisfactory psychometric functioning in preschool-aged children in the German and Italian language versions, with regard to item behaviour, reliability, and factorial structure, and which latent representation of SPS is most appropriate in early childhood? (2) To what extent is the measurement of SPS comparable across the two language versions and key demographic groups (gender and age), as examined through multi-group confirmatory factor analysis and measurement invariance testing within a shared regional and institutional context? (3) To what extent do development-informed item revisions improve the measurement of SPS and its underlying dimensions in preschool-aged children, and what does this imply for epistemic robustness in educational research?

By approaching psychometric validation as an empirical examination of the conditions under which knowledge about children’s sensitivity becomes epistemically accessible and transferable, the paper contributes to international debates on situated educational knowledge, cross-language comparability, and the epistemic responsibilities associated with the use of standardised measurement instruments in early childhood research.

The study is based on a large parent sample of preschool-aged children (age 3–6 years, M = 53.4 months, SD = 10.8 months). The analytic sample comprised N = 3,598 respondents, including n = 3,054 parents completing the German-language version and n = 544 parents completing the Italian-language version of the online questionnaire. Participants were recruited across the vast majority of kindergartens in a multilingual region in Northern Italy. Sensory processing sensitivity was assessed using the Highly Sensitive Child Scale – Parent Report (HSC-PR). The instrument consists of 12 original items, complemented by three revised item formulations that were developmentally adapted for use in early childhood. To examine convergent and discriminant validity, the questionnaire additionally included the Children’s Behavior Questionnaire (CBQ), Very Short Form (36 items), as well as the Hyperactivity/Inattention subscale (5 items) of the Strengths and Difficulties Questionnaire (SDQ-25). All instruments used Likert-type response scales. Analyses are conducted separately for the German and Italian language versions, followed by systematic cross-language comparisons. Analyses include descriptive item-level statistics, internal consistency estimates (Cronbach’s α and McDonald’s ω), and confirmatory factor analyses testing alternative latent representations of sensory processing sensitivity (one-factor, three-factor, and bifactor models). Measurement invariance across language versions (German vs. Italian) and gender is examined using multi-group confirmatory factor analysis. Age-related measurement differences are explored with age treated as a continuous variable. Associations between HSC-PR scores and CBQ and SDQ subscale scores are examined to evaluate convergent and discriminant validity with respect to theoretically related and distinct constructs (e.g., temperament dimensions and hyperactivity/inattention).

The study is expected to provide a differentiated psychometric evaluation of the Highly Sensitive Child Scale – Parent Report for use in early childhood, offering evidence on its reliability, factorial structure, and cross-language comparability in preschool-aged children. By analysing the German and Italian language versions within a shared context, the study clarifies the conditions under which measurements of sensory processing sensitivity can be meaningfully interpreted and compared in early childhood populations. With regard to factorial structure, the study is expected to contribute evidence on whether latent representations of sensory processing sensitivity established in studies with older children are supported in preschool-aged samples, or whether early childhood is characterised by different or less differentiated structural patterns. These findings will inform theoretical assumptions about the dimensionality of SPS in early developmental phases. At the item level, results are expected to show that a targeted, development-informed item revision demonstrates more appropriate psychometric functioning in early childhood than its original formulation, underscoring the necessity of empirical evaluation of item adaptations rather than assuming their validity. Beyond scale-specific results, the study contributes to methodological and epistemic discussions in educational research by framing psychometric validation as an examination of how knowledge about children’s sensitivity is produced and rendered transferable. The findings highlight that in early childhood education research, where standardised parent-report measures inform scientific discourse, professional training, and evidence-based frameworks, inadequate measurement entails risks of misinterpretation and misclassification of children’s sensitivity, which may in turn contribute to epistemically weak knowledge claims and inappropriate pedagogical responses. By establishing a valid early-childhood measure, the study delineates the empirical conditions under which knowledge about sensory processing sensitivity can be generated and meaningfully interpreted in early childhood education research, without turning sensitivity into a diagnostic label.

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