Thematic Mapping and Storyboarding.

An important activity in the development of any multimedia application is that of identifying its underlying structure. This should not be thought of as the arbitrary creation of a 'neat' navigation mechanism (menus, image map, etc.) but as the identification of the 'natural' underlying structure of the content: the categories and conceptual links into which it most naturally divides. This underlying structure may then later be coded as a practical navigation mechanism. As we start to think about implementation then this structure has to be mapped onto sequences of 'screens' of content that will be seen by the user, and we have to keep control of details as they occur to us.

There are two diagrammatic tools that help us in this process. In the early stages of our thinking we can express our explorations of the structure of our application with a thematic map. Later on, as we start to descend to the fine detail of our application this map is transformed into a storyboard. Let us examine these two tools in detail.

Thematic Map.

A thematic map can be thought of as a 'road map' showing how our content subdivides into self-contained categories, and the ideas which link them together. On an analogy with a road map we might say that the categories are our towns and villages, and the linking ideas are our roads. The overall shape of our material corresponds to the topography of a mapped region. Just as maps can be at different scales, so can our thematic maps show different levels of detail. In the early stages of our thinking we confine ourselves to the principal categories of content and linking ideas; later on the detail of our 'content countryside' starts to emerge.

To give you a more precise idea of what is meant by 'category' and 'linking idea' in this context (since I am using these words in a specific sense). Think of a category as a heading under which we place a chunk of information, and a linking idea as one which takes us to another, related category of information. To take a simple example, suppose that we were trying to design an art history application along the lines of the National Gallery's cd-rom. We might gather the oil paintings of an artist into a single chunk of information; a linking idea such as 'medium' might take us to a discussion of the characteristics of oil and canvas, or that of 'artist' might take us to a biography, or that of 'cultural background' to the ideas and events that inspired the paintings, etc.

A thematic map is an informal version of the 'entity relationship diagram' used in database design, and a generalised version of the 'mind map' popular in business and educational circles (mind-mapping often seems to over-emphasise hierarchy and a central idea).

During the development of a thematic map it is necessary to try and identify the 'natural' structure of our content. It is useful to try and detect the characteristics that correspond to some common, broad structures:

• Hierarchical Structures. If we are representing orderly knowledge structures (the kind of information stored by an encyclopedia or text book), or the structure of a formal organisation (a company, a university, etc.) then we should expect to detect a hierarchy of categories linked by a hierarchy of ideas.
• Linear Structures. If we are representing a narrative then we are dealing with a structure that is fundamentally linear (with perhaps some asides and sub-plots).
• Circular Structures. If we are representing a tour of some place then we are dealing with a structure that is fundamentally circular (with perhaps some detours and extra 'loops').
• Other Structures. There is no end to the structures that may be detected in content. For example, these notes are represented as a rectangular grid because I felt that that they could be varied in two dimensions: the progress through the semester, and the degree of independent study involved.

Storyboard.

The storyboard is a tool used in film making. It consists of representing the unfolding narrative of a film as a sequence of sketches. Like the thematic map it too can be used at different levels of detail. At the highest level of detail it might only consist of sketches for each of the major scenes of a film, giving a rough indication of the narrative. As detail is added sketches are drawn for every shot, lighting and sound directions appear, dialogue is added, technical specifications for shooting are added, etc. Some specialised storyboards link action, sound and musical score (these help the director and composer collaborate).

When this technique is adapted for multimedia the content of the storyboard changes: sketches of sets and actors are replaced by screen layouts; lighting, sound and dialogue become a specification of the 'assets' (see next week's notes) essential to the current screen. Also, because multimedia is non-linear (a film unfolds linearly, a multimedia presentation can loop and branch) its storyboards can be linked into arbitrary structures and directions of movement through it should be indicated explicitly.

A storyboard shouldn't be seen as just another form of the thematic map; it is a distinct and (usually) later part of the design process. A thematic map explores the conceptual structure of the content of an application; a storyboard organises this content into screen layouts and practical navigation structures. A storyboard will be based on a thematic map, but it doesn't just slavishly copy it. Another level of design thinking is involved. For example, a thematic map might have a single category on it (e.g. the oil paintings of a specific artist) which has to be unfolded into a sequence of screens in a storyboard (e.g. we might loop through those paintings in an animated slideshow). In other cases we might wish to collapse a portion of the thematic map into a single screen (e.g. this current web page contains a complex of distinct ideas, but it would be impractical and disorientating to give a page to each of them).

In some cases it might not be necessary to develop a thematic map before storyboarding - this will happen when no real conceptual analysis is necessary. The 'ghost story' application is a case in point; you don't have to analyse a body of ideas, you simply have to adapt a well-written narrative. Go through the development of a storyboard for the ghost story. Start with a few simple sketches of the main lines of your adaptation until you think you have an appropriate structure and content. Then expand your storyboard into a detailed specification. Show all the routes through the adaptation; specify all the images, text, sounds, etc. each screen needs; indicate the navigation panels, etc.; show screen layouts in detail and indicate the colour schemes.