This paper, designed to be used in conjunction with a video-tape developed by the Learning in Science Project (Primary)--LISP(P)--shows excerpts from some of the interview schedules used to examine children's ideas about floating and sinking. These interviews involved the use of "interview-about-instances" (IAI) cards (included in an appendix) to examine what children mean by the word "floating," and the use of different materials (listed in another appendix) to examine several additional areas. These areas include: (1) which materials float and which materials sink; (2) a child's idea about the effect of the depth of water on floating; (3) a child's idea about the effect of the length of an object on how well it floats; and (4) a child's ideas about displacement. (JN)