Classic research has also found that the presence of a human form may affect viewing behaviour (Nixon,1925; see also (Kroeber-Riel,1979) citing a study by Witt,1977 concerning the level of undress exhibited by a figure in an advertisement). Research in scene perception indicates, however, that when attempting to discover effects of high-level, semantic aspects of a stimulus, it is important to control for possible difference in low-level visual salience (see Rayner,1998 for a discussion of such considerations). Future research could build upon these early studies,then,by determining and attempting to control for differences in low-level visual salience across ads, thus allowing us to draw stronger inferences about the possible role of these higher-level, semantic factors.