00:01So, I want to be, not contrarian, about terminology, but offer refinement.
00:08And I want to talk about diagrams because I think they're really, really interesting.
00:15And essential to our enterprise.
00:17And they're like maps, and they're like sketches, both words that we've been tossing around quite a lot lately.
00:24But they're unique.
00:27I think most of us can call that a sketch.
00:30It had characteristics of having been made quickly.
00:32It has characteristics of representing some real-world attributes like texture sometimes, or color, or outline, et cetera.
00:43Many of you will recognize that as a map.
00:46It also has some relationship to some real-world stuff.
00:50Either shape or scale, but not both.
00:55And other kinds of abstractions to be sure, but kind of one-to-one mappings.
01:00That's one reason we call it the map to the world.
01:04And then there are these critters called diagrams, which are graphic things.
01:10And they talk about, or represent, or abstract, real-world and spatial things, but in a different way.
01:19And in critically different ways.
01:23Diagrams graphically represent high levels of abstraction, just as maps do...
01:28...and perhaps in a different way that sketches and photographs do.
01:34They emphasize critically elements and relations, a good basic database concept, such as topology, for example.
01:47Duality, singularity, and other kinds of high-level topological constructions...
01:53...rather than, for example, measurement or detail that you would find often in a map or a sketch.
02:01And they're often used in the process of explanation or argument...
02:05...whether with yourself or your client, your instructor, your students, your colleagues.
02:12There are many kinds of familiar diagrams in different disciplines.
02:17They all have the characteristics I talked about, having elements and relations in them.
02:22They use color.
02:24They often use arrows for various reasons.
02:28They are...even though they may...some of them are more maplike than others.
02:33They're not maps in ways that we can distinguish them, and to be sure, there are...
02:38...this is a continuum, and there are sketchlike maps, and there are maplike diagrams.
02:41And there are things that are odd hybrids that we can't quite figure out until we see how they're being used.
02:46And that's an important part of the thing here.
02:50Here's a famous one. Garden Cities of the Future, Ebenezer Howard.
02:56This is a fragment of a larger diagram, and he says, "Note: This is only a diagram."
03:03We can't make the plan; we can't make the map...
03:06...and I'll use those two terms interchangeably for now...
03:08...until we have a site.
03:10So there's something different here.
03:12This is a set of concepts, ideas, elements, and relations that have yet to land on the ground.
03:20And when they do land on the ground...
03:22...then they will generate maps and plans and work orders and construction equipment and all that kind of stuff.
03:29And here's a canonical, familiar bubble diagram from the architectural and land planning enterprise...
03:36...where once again, we see elements and relations and topological constraints like connectedness and maybe family relationships...
03:46...where color is used to designate there's something the same about these, but we don't know what it is, perhaps, even.
03:52Or maybe we can begin, it's so obvious what it is.
03:54And there's a very simple graphical palette that's constrained by all those semiotic rules...
03:59...that Bertrand and others have helped us understand the uses of...
04:03...that are used to map these concepts, not their terrain-based implementation.
04:11But what's so cool, I think, and interesting, and fabulous, and important, about these...
04:16...is that in fact they have this...some kind of a relationship to maps.
04:21They can be derived from maps.
04:23We can look at a map or a plan and diagram it.
04:26Or, we can take a diagram and instantiate it as a map or a plan.
04:32And so they hold this interesting...
04:36...dare I say, epistemological relationship to what we know and how we know it, and where it lands...
04:42...in the birth of maps and plans, and the design process.
04:48And Carl showed us multiple examples of diagrams in his talk this morning.
04:49So, to reiterate, diagrams embody concepts, or ideas, like inside and outside and edge and large and many.
05:01And if you go back and listen to the video of his tape...
05:04...you'll see he talked about diagrams and he said that designs are different 'cause they have different diagrams.
05:10I collected these diagrams and we combined them.
05:13And I kind of knew what he was going to talk about, but I didn't actually set him up to say all that.
05:19Ideas can be implemented and manifested in diagrams, and diagrams can generate maps.
05:26And you can run this back.
05:28You can say, from this map let's extract the diagram.
05:30Let's see what the ideas embedded therein are.
05:34Now one important role of this is if you want to make a change...
05:39...you can take your map up to the diagram and plat the diagram in a different terrain; a different site.
05:44Maybe you'll have a different map, and a plan, but the same diagram.
05:48And it's a one-to-many relationship.
05:50There can be many ideas embedded in a diagram.
05:52A diagram can generate many maps.
05:55A map can embody many diagrams together, as we've seen.
06:01In object-oriented terminology then, that sort of idea that's frankly borrowed from Lenaeus, and it manifests in modern programming...
06:11...you could say that diagrams are instantiations of ideas, so ideas are classes in a sense...
06:19...and diagrams become instances of them, and maps and plans, in turn, are instances of the diagrams.
06:26And it's a, I believe, lattice rather than a simple hierarchy, so that indeed, a diagram can have multiple ideas.
06:35And a map can have multiple diagrams.
06:38But these are three very different levels of inferentional...inferential argument and discourse.
06:47We talk about the map, so we care whether there's a cliff, and an obstruction, and a south facing.
06:54The idea was very simple. Two nodes and a line between them.
07:02So diagrams support logical analysis and inference as well as spatial.
07:09And that's important, because we talk about these in slightly different terms interchangeably.
07:14And logical analysis is not necessarily visual, whereas spatial analysis of maps often is.
07:21And diagrams sit in between here and support both kinds of inference.
07:26Well, if the cliff is between these things, then there's a problem.
07:30That's a spatial inference.
07:32That they are connected is an ideological concept, or even logical.
07:38I bow to the diagrams made by ModelBuilder...
07:40...but they're a small subset of all the kinds of diagrams that we need to be able to support in this process.
07:46Here's an example from the planning literature.
07:48This city river district diagram describes the recurring relationship.
07:53It further suggests potential linkages.
07:55The same elements that the generic diagram (city center, main street, peripheral 00:08:15
08:03...one role of a diagram is to be able to say, what's similar about this situation and that situation...
08:09...which are very different terrain and topography, but have similar urban functioning or connected kinds of roles.
08:15And you could take this diagram and create a map from it.
08:19Or you could look at a map and derive a diagram from it.
08:22But we don't have very good tools for doing that other than the human eye-brain combination.
08:29Here's a diagram that I caught in the wild this fall at the GSD.
08:35And I didn't have my camera with me, so I had to reconstruct it.
08:39You may not know what it is yet.
08:41What if I tell you that's a waterway?
08:46That's a highway.
08:48That's some green stuff.
08:51And that's some built stuff.
08:54Well, then that diagram can be instantiated.
08:58And the differences between the instantiation of the diagram can be noted.
09:05And here's a diagram that's a different plan of the same diagram.
09:11And the diagram possibly needs yet another diagram that says they don't have to be parallel.
09:17And the highway doesn't always have to be between the green and the blue.
09:22And they can go under bridges and get intermixed.
09:25Those are design concepts that we want to be able to record and move forward with.
09:30And so, the act of putting down this one is a lot like building a legend.
09:35And whether the legend or the diagram comes first, I don't know.
09:38But making a legend and making a diagram are exchangeable, interactive parts of the design process in important ways.
09:47And there's an instantiation of that, with some green stuff and some gray stuff and a highway.
09:54And on it goes.
09:57Diagrams are subject of active research.
10:01My Ph.D. thesis at MIT had diagrams in the title.
10:04That was 20 years ago, and in the last decade...
10:07...here, for example, is the fifth international conference on diagrams and diagrammatic representation and inference.
10:13The artificial intelligence community is very interested in these things for, I think, exactly the same reasons I've talked about.
10:20The interesting potent inferential role they play...
10:24...in graphical and visual knowledge and intelligence and other domains of argument and representation.
10:34So diagrams are distinguished not so much by their graphic style and conventions...
10:38...although there are many of them, and we teach and promulgate them and sometimes invent and break them...
10:43...but by their roles in design inference.
10:47And they're not sketches. And they're not maps.
10:49But they function halfway in between concepts on the one hand and maps on the other hand.
10:59And that's what makes them, in my view, so potent.
11:03Whether something is a map or a sketch or a diagram depends a little bit on how it's used, not so much...
11:08...you can't always tell by looking at it.
11:12But I believe they're essential in our GeoDesign enterprise, and that they require their own research agenda and software support.
On the Necessity of Diagrams
Stephen Ervin of Harvard University delivers a fascinating presentation about object-oriented diagrams in GeoDesign at the 2010 GeoDesign Summit.
- Recorded: Jan 5th, 2010
- Runtime: 11:27
- Views: 21645
- Published: Aug 25th, 2010
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