This multiple case study describes error-reaction patterns (ERPs) in middle school science lessons. Twenty-seven science teachers' reactions to student errors were explored in terms of four aspects of classroom discourse: talk move, discursive purpose, communicative approach, and patterns of interaction. Two hundred ninety-six error-reaction occurrence moments captured from 4089 min of science lessons were analyzed. Nine types of ERPs were extracted around three higher-order categories. "monologic declarative and dialectical." The study presents evidence that the declarative error reactions may be a pre-condition to enacting the dialectical ERPs, and the occurrence of ERPs may be teacher-specific. Educational implications are offered regarding the science teacher's noticing of the ERPs.