Educators working with elementary school children need to consider the impact of unstructured and structured hypermedia on the learning occurring in computer-assisted instruction. This paper discusses a case study of a collaborative group of four boys during a summer science camp. Their interactions with two different examples of hypermedia are observed. One program was a structured hypermedia approach that provided a framework for exploring videodisc information while exploring a hands-on activity. The second program was an unstructured hypermedia environment. The children used the hypermedia in different ways: with the unstructured hyper-environment, the children were satisfied to rely on visuals to gain information; with the structured hyper-environment, the children worked through the activity using the steps followed in the program. Teachers wanting to use the hyper-environment as a way to explore hands-on investigations using the computer should look for structured hypermedia programs. (Contains 6 references.) (JLB)