Surface structure and deep structure

By Gordon Rugg

The concepts of surface structure and deep structure are taken for granted in some disciplines, such as linguistics and media studies, but little known in others. This article is a brief overview of these concepts, with examples from literature, film, physics and human error.

The core concept

A simple initial example is that the surface structure of Fred kisses Ginger is an instantiation of the deep structure the hero kisses the heroine. That same deep structure can appear as many surface structures, such as Rhett kisses Scarlett or Mr Darcy kisses Elizabeth Bennet.

There are various ways of representing surface and deep structure. One useful representation is putting brackets around each chunk of surface structure, to clarify which bits of surface structure map onto which bits of deep structure; for example, [Mr Darcy] [kisses] [Elizabeth Bennet].

Another useful representation shows the surface structure mapped onto the deep structure visually. One way of doing this is as a table, like the one below.

Continue reading

An introduction to graph theory

By Gordon Rugg

Graph theory is an extremely powerful approach that is based on a handful of elegantly simple concepts. It was invented by Euler in the 1740s, and is a central part of modern mathematics and technology. Among other things, it plays a key role in handling traffic on the Internet.

It’s invaluable for representing knowledge, because it combines flexibility with formalism. In particular, it’s useful for representing different facets and viewpoints; for representing hierarchies of goals and values; for representing successive layers of explanations; and for formal taxonomies. Continue reading