Editorial on the Research Topic Scale Development and Score Validation Scale development and validation of scores is not a job to be taken on lightly. Development is a rigorous process which is based on item generation and content validation using expert feedback and pre-testing. In fact, it may take numerous iterations for the scale to be economically feasible and yet convey the appropriate construct. After the scale has been qualitatively developed, it goes through a rigorous quantitative examination to evaluate its score reliability and validation. This validation may include construct, concurrent, predictive, concurrent, and discriminant. For example, there are numerous techniques for evaluating construct validity such as using exploratory factor analysis (EFA) followed by confirmatory factor analysis (CFA) or using a structural equation model (SEM). Of course, determining the number of factors in an EFA can be quite a problem. Many researchers use the classic Scree test or Kaiser's eigenvalue-greater-than-1.0 technique. However, some studies suggest that these may not be the best techniques (e.g., Lloret-Segura et al., 2014). Other procedures have been developed that allegedly have better psychometric properties, such as Velicer's MAP, parallel analysis, Ruscio and Roche's CD technique, and Achim's NEST method. Another problem with validation is that the participants are often a single sample (usually college students), which can limit the generalizability of the findings even though cross-validation could still be used. However, we are beginning to witness questionnaires or scales translated into a variety of languages so that factor structures and factor scores become comparable. This cross-cultural work may aid in assessing measurement invariance. This Research Topic welcomed all types of empirical articles focused on the analysis of the psychometric properties of the measurement instruments in any psychological or social science area. A total of 107 authors contributed 22 articles to the Topic. These articles can be organized intro four issues: (1) Scale development with solid psychometric score validation techniques; (2) Cultural adaptation of developed scales (3) Validation of scores on developed scales, and (4) Invariance measurement of developed scales. SCALE DEVELOPMENT WITH SOLID PSYCHOMETRIC SCORE VALIDATION TECHNIQUES Gorostiaga et al. developed and examined the psychometric properties of the Entrepreneurial Orientation Scale (EOS) in a sample of undergraduate students. The EOS showed good