Two studies investigated children's metacognition about everyday reasoning, assessing how they distinguish reasoning from nonreasoning and "good" reasoning from "bad." In Study 1, 80 1st graders (6-7 years), 3rd graders (8-9 years), 5th graders (10-11 years), and adults (18+ years) evaluated scenarios where people (a) used reasoning, (b) solved problems with nonreasoning approaches, or (c) reacted appropriately but automatically to events. All age groups distinguished reasoning from type (b) nonreasoning cases, but age-related improvement occurred for type (c) cases. Study 2 tested 160 1st, 3rd, 5th graders' and adults' evaluation of good and bad reasoning processes, finding 2 developmental changes: initial improvement in discriminating thinking processes by 3rd grade and emergence of an adult-like, process-focused (vs. outcome-focused) concept of thinking quality by 5th grade.