This study investigated the meanings and ideas held and questions asked by children (ages 7-14) about floating and sinking (in water). Data were collected from interviews using "interview-about-instances" (IAI) cards (included in an appendix) and 10 objects which either floated or sank. Additional data were collected from classroom surveys and from lessons designed to elicit student questions and answers about the topic. Student responses are presented, discussed, and analyzed in separate sections addressing: (1) children's meanings for the work "floating"; (2) children's explanations of why things float or sink; (3) ideas relating to the effect on floating material if the object is changed or the depth of displacement of water is altered; and (4) children's questions about floating and sinking. Responses are categorized within each section by major patterns noted during analyses. The interviews revealed that different children attached different meanings to the word floating, which varied with context (such as observing real objects in water as opposed to viewing line drawings) and that these meanings in some cases differed from those of scientists. In addition, children had a range of views about why some things floated while others sank. Implications for science instruction based on these and other findings are noted. (JN)