This is the first of a two-part article, the second part of which will appear in this year's Autumn issue ofElectronics Education.In this article no attempt has been made to provide an historical summary of the data capture devices and systems which have been used in classrooms since the introduction of the microcomputer or to review the range of data capture equipment available at the present time. Rather, it is hoped that this paper will provide the reader with an outlineof a complete data capture system and an understanding of the criteria by which he/she may select a suitable data captur system from those available.