Comments by Johanna Drucker on internet: The concept of the "diagram" is vaguely defined in common usage, used to refer to a broad variety of schematic images"”graphs, charts, anatomical images, working drawings and so on. By working towards a tighter definition, we might use the term to refer to a specific category of graphical expressions that spatialize relations. These relations, I suggest, are themselves meaningful"”they are a kind of poetics, a bringing into being of meaning through articulation and expression. The materiality of this poetics of relations provides a way to analyse its formats and features"”to get at, to grasp, to read, see, describe, elaborate the particulars of diagrammatic expressions. The even more specific attention to writing, to written discourse organized in graphical form, exposes the workings of diagrammatic activity within the field of visual verbal activity. We depend upon these, but rarely stop to describe or discuss their structuring principles or effects.A diagram is an image that works, it does something, it provokes and supports performative engagement by virtue of its structures and the relations they express. A diagram is a graphic expression of semantic values in spatial form whose specific visual features constitute the semantic values. Diagrams are performative, rather than representational, and an approach to diagrammatic writing that engages with such graphical principles expresses relations that might be expressed through other means"”mathematical formulae, textual description, logical propositions. But their graphical materiality makes them available, accessible, and also, makes their historical lineage apparent. So, though some diagrams are graphic, the principles of diagrammatic thinking are not exclusive to graphical expressions. (A concept of the hierarchy of power relations or kinship relations, for example, can be understood diagrammatically and expressed visually, but the relations of subordination, exclusion, proximity, prohibition and taboo do not depend on graphical forms for either their enactment or their apprehension in a human community.)Diagrammatic writing makes use of specific features of graphical codes. All writing is graphical, by definition, and the graphicality of all writing plays a part in the production of its legible and communicative, expressive, value. Whether by virtue of the reading of stylistic codes, of the place and situated-ness of an inscription (formal monumental writing, informal graffiti, printed communication, official signage and so on), we are able to distinguish orders, genres, types of written language in a millisecond, long in advance of processing textual content. But graphicality and diagrammatic properties are not interchangeable. Pictures are graphical, but they don't work in the same sense that diagrams do. Representational images are constrained by analogy. Their referential identity determines their form rather than having their form arise from or express values through relations. More forms and formats of writing contain and make use of diagrammatic features than is generally realized. For instance, the basic scoring of prose through the use of word spaces, punctuation, paragraph markers, and so forth creates a fundamentally diagrammatic work. Why? Because the elements of the graphical encoding allow the work to be read as a text predigested by its graphical structure. We have only to take the precise same set of letters and order them alphabetically to recognize that graphical sequencing and chunking are significant. Likewise, in reckoning a mathematical sum, we take advantage of diagrammatic graphic features to align columns of numbers according to the place value of integers. Try adding a set of numbers that has been scattered around the perimeter of a room instead of put in a neat column and the supporting role of graphical organization and scoring becomes quite evident. -- Source of annotation: Marvin or Ruth Sackner.