What is a presentation?
Lobin (2012: 9) traces presentations as we know them today to settings in which visual aids (maps, tables and the like) are displayed, interpreted and perhaps discussed in a group. Since presentations began to make use of computers and video projectors (their predecessors, slide and overhead projectors, are now almost forgotten), the opportunities for visualisation have increased immeasurably. Admittedly, a presentation is essentially a “speech” (in the broadest sense, as a form of oral communication). However, as Lobin stresses, hardly anybody who presents under present-day conditions, where it is a matter of explaining, interpreting and assessing information, often in the form of figures or charts (cf. 2012: 9), has ever made a “speech” in the traditional sense. The dominant role of visual elements implies the use of deictic means. Thus the presenter can point at an actual object (rather a special case) or at pictorial representations of different kinds and with different levels of abstraction (see Section 3.5).
Howell and Bormann (1971: 7-10) date the change of paradigms at around the middle of the 20th century, when “presentations”, or, even more generally, “presentational speaking”, became a tool used in management decision-making processes in (US) companies - just as the requisite presentation media became available. These authors include various photos of “historic” exhibits such as the “flannel board”, the “filmstrip projector” or the “overhead transparency making machine” (pp. 248-255).