The Software Infrastructure Attitude Scale (SIAS): A Questionnaire Instrument for Measuring Professionals’ Attitudes Toward Technical and Sociotechnical Infrastructure
\textbf{Context:} Recent software engineering (SE) research has highlighted the need for sociotechnical research, implying a demand for customized psychometric scales for SE. \textbf{Objective:} We define the concepts of technical and sociotechnical infrastructure in software engineering, and develop and validate a psychometric scale that measures attitude toward them. \textbf{Method:} Grounded in theories of infrastructure, attitudes, and prior work on psychometric measurement, we defined the target constructs and generated scale items. The items were reviewed and refined by domain experts. The scale was administered to 225 software professionals and evaluated using a split-sample. We conducted an exploratory factor analysis (EFA) on one half of the sample to uncover the underlying factor structure and conducted a confirmatory factor analysis (CFA) on the other half to validate the structure. Further analyses with the whole sample assessed face, criterion-related, and discriminant validity. \textbf{Results:} EFA supported a two-factor structure (technical and sociotechnical infrastructure), accounting for 65% of the total variance with strong loadings. CFA confirmed excellent model fit. Face and content validity were supported by the item content reflecting cognitive, affective, and behavioral components. Both subscales were correlated with job satisfaction, perceived autonomy, and feedback from the job itself, supporting convergent validity. Regression analysis supported criterion-related validity, while Heterotrait–Monotrait ratio of correlations (HTMT), the Fornell–Larcker criterion, and model comparison all supported discriminant validity. \textbf{Discussion:} The resulting scale is a valid instrument for measuring attitudes toward technical and sociotechnical infrastructure in software engineering research. Our work contributes to ongoing efforts to integrate psychological measurement rigor into empirical and behavioral software engineering research. The scale can also be used by companies and organizations to assess their employees’ attitudes toward the infrastructure they provide.