This paper is intended as a contribution to the continuing discussion on the problem of site definition in surface survey. The data are drawn from the results of surveys undertaken by the author on the islands of Kephallenia and Lefkas off the western coast of Greece. Following a brief description of the islands, the aims and strategies of the surveys are described. Some methodologies are then proposed that can aid the researcher in the decision-making process in the field and allow for testing and reassessment of those decisions later. It is argued that sites are only part of a continuum of artifact distribution and that they can only be defined in relation to visibility and to the level of surface artifact density across the entire study region; this material is also referred to as ``background noise.''