Quantitative research, in the context of curriculum studies, is defined as research about curriculum that collects and analyzes information and data that are represented by numbers. In this entry, quantitative facts, claims, and data are contrasted [Page 708]with qualitative information. Research methods and designs that are commonly used in quantitative research are identified and described. The last section of the entry addresses five central concepts that are used in the design and conduct of quantitative research: internal and external validity, hypothesis testing, and reproducibility and generalizability.