Reform‐based science instruction is guided by teachers' normative beliefs. Discursive claims are how teachers say they teach science. Previous research has studied the change in teachers' beliefs and how beliefs influence intended practice and action in the classroom. Few studies have connected what teachers believe, how they say they teach, and how they actually teach in the classroom. The purpose of this study was to investigate how a teacher's normative beliefs, discursive claims, and classroom practices were related to the implementation of reform‐based standards. This research study analyzed 78 secondary science teachers' beliefs and claims about teaching in a reform‐based, innovative manner. A subset of teachers was observed in the classroom to determine the relationship among beliefs, claims, and implementation in the classroom. The study revealed that there is a disconnect between what science teachers believe and what they say about science teaching. A teacher with traditional normative beliefs and innovative discursive claims implemented reform‐based pedagogy. Beliefs alone were not a good predictor of innovative teaching, whereas discursive claims were determined to be a better predictor for implementation of reform‐based science teaching. Innovative discursive claims, regardless of the type of beliefs, resulted in innovative teaching. A Normative‐Discursive‐Practice Model is proposed to guide research about beliefs and claims leading to classroom implementation. The conclusions indicate that determining teachers' discursive claims is more informative for planning professional development than determining or monitoring their beliefs. © 2015 Wiley Periodicals, Inc. J Res Sci Teach 53: 1419–1443, 2016