The main research question of this research study is how to design a valid and reliable holistic rubric to be used as a criterion for the comparison of the STEAM model by analyzing different countries' science curricula. Considering this question, STEAM model rubrics was created by examining the ways of shaping science education policies. The research was qualitative, and the design of this research was descriptive. Document analysis was carried out for data collection process. Content analysis was used for analyzing data. The raters selected conveniently from science education and measurement evaluation fields were asked to rate the Turkish and Finnish Science Curricula as documents through the developed rubric. The rating process was carried out by associating appropriate themes obtained from literature. Sub-dimensions of the rubric developed were examined by teachers and researchers who are experts in the STEAM fields, measurement and evaluation. For calculating the reliability, the researchers graded a content about the Turkish and Finnish Science Curricula from the STEAM learning areas with this rubric. Fleiss Kappa and Miles Huberman consistency statistics were used for providing inter-rater validity. It obtained valid and reliable criteria for making significant contributions and comparisons of the STEAM model in science education policies.