There is general agreement that the laboratory provides science students with unique learning experiences. The laboratory utilizes manual and intellectual skills, which are in some measure distinct from those used in non-laboratory work. A comprehensive review of the literature, conducted by Lazarowitz and Tamir (1994), summarized the aims and objectives of laboratory work. These authors suggested that laboratory work be structured under the following main headings: understanding of concepts, acquiring habits and capacities, gaining practical skills (including planning and design of a practical exercise, performance, organization, analysis and interpretation of data, and application to new situations), appreciating the nature of science, and developing attitudes. Whether these aims and objectives are attained, and the form of laboratory work conducted, depends very much...