Counting an Unwritten Population: The Terrace Houses of a Hill Town
A hill town occupies 9 hectares, of which 5.5 ha are built-up terraces, 2 ha are cisterns, courtyards, and streets, and 1.5 ha are steep slope unsuitable for housing. Survey recorded 140 ground-floor room units within the built-up area, but only 60 percent of the town has been intensively surveyed; the rest was sampled by transects giving a density estimate of 22 rooms per hectare. Average room size is 14 square metres. Ethnographic comparanda from the region suggest 4 to 6 square metres of roofed domestic space per person. The excavator proposes a peak population of 4,000. A reviewer argues the figure should be nearer 1,200. Neither cites a method. The ceramic chronology suggests the town was occupied for about 250 years, with a peak in the middle century.
1. Build a defensible population estimate from the room data and identify the largest source of uncertainty.
Read the worked answer
Step 1, estimate total rooms. Intensive survey found 140 rooms in 60 percent of 5.5 ha, i.e. 3.3 ha, giving about 42 rooms/ha. The transect estimate of 22 rooms/ha is much lower, probably because transects miss courtyard interiors and upper storeys. A reasonable range is 22-42 rooms/ha across 5.5 ha: 121-231 rooms, midpoint about 175. The observed 140 is a floor, not a total.
Step 2, convert to roofed area. At 14 m² per room, that is 1,700-3,230 m² of ground-floor domestic space.
Step 3, apply density. At 4-6 m² per person, ground-floor space alone gives roughly 280-810 people. This already shows the 4,000 figure is unsupportable by ground-floor rooms.
Step 4, consider upper storeys. If half the rooms carried a second floor, add 50 percent, giving roughly 420-1,200. The reviewer's 1,200 sits at the top of this range and is defensible only if upper storeys were common and density was 4 m²/person.
The largest uncertainty is not room count but the space-per-person ratio and the proportion of two-storey buildings; neither is directly observable. Reporting a range with stated assumptions is more honest than a single figure.
2. The excavator's 4,000 and the reviewer's 1,200 differ by more than a factor of three. Diagnose how each figure could have been produced and say which assumptions each silently relies on.
Read the worked answer
The 4,000 figure is only reachable by stacking generous assumptions: treating all 9 ha as residential (not 5.5), assuming dense multi-storey occupation, and using a very low space-per-person figure. For example, 9 ha at high room density with three storeys and 3 m²/person could approach 4,000. Each step inflates: the 3.5 ha of streets, cisterns, and slope are not domestic, and 3 m²/person is below the ethnographic range given. The figure therefore depends on silent assumptions about storeys and crowding that the evidence does not supply.
The 1,200 figure is reachable by taking the observed 140 rooms, assuming one storey, and applying 4 m²/person with a modest correction for unsurveyed areas. It silently assumes upper storeys were rare and that room counts equal domestic units, ignoring that some rooms were kitchens, stores, or workshops.
The real disagreement is about storeys and room function, not about survey coverage. The correct response is to state the assumptions explicitly and present a range (roughly 400-1,200) rather than defend either endpoint.