Diagramming Intent — Analysis vs. Inventory
A diagram that only shows what exists gives a designer nothing to respond to. A diagram that reveals what it means gives a designer a direction.
An idea with deep roots in landscape architecture
In 1969, Ian McHarg published Design with Nature and introduced overlay mapping as a method for ecological site analysis. The process was straightforward: draw each site system — geology, hydrology, vegetation, wildlife, slope — on a separate transparent layer. Stack the layers. Where they overlap, patterns emerge that no single layer contains. The composite reveals constraint, opportunity, and relationship that is invisible in any individual dataset.
This is the intellectual foundation of the approach you are learning here. McHarg was working with hand-drawn acetate overlays and physical light tables. You are working in Illustrator with vector layers and Pathfinder operations. The method is the same: individual factual layers are the raw material, and the analytical insight lives in their intersections. What has changed is the tool. What has not changed is the epistemological claim — that analysis is a relational act, not a descriptive one.
What inventory looks like
Before describing what analysis is, it helps to be precise about what it is not — because the difference is not always obvious in the finished product. An inventory diagram records facts. It shows where pedestrian paths are, where trees exist, where the road edge falls. This is useful. It is the necessary raw material for analysis. But it is not analysis.
Inventory diagrams have recognizable signatures: their titles describe topics rather than claims ("Site Circulation," "Vegetation Map," "Existing Topography"). Their content shows location and category without revealing relationship or implication. They could be produced without visiting or thinking about the specific site — only the geometry changes. And crucially: a designer looking at an inventory diagram cannot determine from it alone what their design needs to do. The diagram has transferred information, but has not performed analysis.
Most diagram instruction — and most student work — produces inventory. This is partly because the assignments that generate diagrams are often framed as documentation tasks ("show the site circulation"), which correctly produces documentation. When the task is framed analytically ("reveal what the site's current circulation patterns mean for a design"), the same student produces something substantively different. The framing of the task determines the thinking that happens.
What analysis does differently
An analysis diagram takes factual layers and asks what their relationship reveals. The individual layers are inventory. The intersection — the compound condition — is the analysis.
A single layer showing where people walk is inventory. A compound diagram showing where pedestrian paths, bicycle routes, and vehicular access intersect — and identifying the zones where all three compete for the same space — is analysis. The analytical content does not live in any single layer. It emerges from their overlap. A designer looking at that compound diagram can answer the question: "What must my design address here?" The zones where the three systems conflict are the highest-priority safety and wayfinding interventions on the site. No single-layer diagram produces that finding.
Another example: canopy coverage (one layer) layered against documented gathering areas (second layer) layered against solar orientation (third layer) reveals which gathering spaces are thermally comfortable at which times of day. Each layer independently is inventory. Together they reveal a design constraint on programming decisions that is invisible in any individual dataset.
The test
After looking at your diagram, can a designer answer the question: "What does my design need to do in response to this?"
If the answer is no — if the diagram shows what is there but not what it means — it is inventory. Keep going.
A secondary test: can the diagram be titled as an argument rather than a topic? "Pedestrian/Vehicular Conflict Zones" is an argument title. "Site Circulation" is a topic title. "The Eastern Edge Creates a Structural Barrier Between Two High-Use Program Areas" is a stronger argument still — a specific claim about this specific site that implies specific design responses. The title is where the analytical claim lives, and if you cannot write it, the analysis is not complete.
Diagram types for this site
The following analytical questions are starting points. Your diagrams must emerge from genuine inquiry about the specific LA226 project site, selected in consultation with the LA226 studio professor. A type name is not an analysis. The analytical question it should answer is.
| Type | The analytical question it should answer |
|---|---|
| Circulation and movement | Where do pedestrian, bicycle, and vehicular flows share space, conflict, or create safety and accessibility failures? Where is intensity concentrated and where is it absent? |
| Use intensity and programming | Which areas are over-used, under-used, or used in ways that conflict with adjacent activities? Where does demand exceed supply, and where does supply sit unused? |
| Ecological systems | Where is canopy ecologically meaningful versus isolated? Where do ecological corridors exist or are interrupted? Where do site systems create microclimatic conditions a design should respond to? |
| Edge and threshold conditions | Which edges are hard barriers to movement or use? Which are permeable? Where do transitions between zones create spatial deadfall or deny sequence? |
| Topographic opportunity and constraint | Where does grade change limit buildable area, create drainage concentration, or produce spatial compression and expansion that a design can work with or must work around? |
| Accessibility, wayfinding, and legibility | Where does the site's wayfinding system fail? What ADA constraints limit design options? Which entry points are legible and which are ambiguous? |
| Views, borrowed landscape, and visual connection | Which off-site conditions should be preserved, framed, or screened? Which internal sight lines create spatial axis or sequence that a design should reinforce or interrupt? How do views compound with use patterns to create or deny meaningful spatial experience? |
| Amenity proximity and service distribution | Which populations are well-served by existing amenities and which are not? Where are service gaps? What areas need infrastructure that does not currently exist? |
Try this
Write the title of your diagram before you draw a single line. Not "Circulation Diagram" — an argument: what does this diagram claim about the site? If you cannot write the title yet, you do not know what you are analyzing. Spend time with the site, the plan, and the model until you can state a specific claim. Then build the diagram to prove it. Every factual layer you add should be there because it contributes to the argument in the title, not because it was on the list of diagram types.
When the diagram is complete, cover the title and show it to someone who has not seen it. Ask them what claim the diagram is making. If their answer matches your title, the diagram is communicating its argument visually. If it doesn't, either the diagram or the title needs revision.