CRED.(The Talk of the Town)

It is no sign of disrespect that the city's plan for counting its over-all homeless population is modelled, in part, on wildlife research--estimating harvestable stocks of Danish fish, or observing the density of elk on the Olympic Peninsula. Nor is it meant to offend that the plan calls for sending dozens of graduate students, more shabbily dressed than usual, into the streets for a night of homeless playacting alongside the truly suffering--a role, incidentally, for which each student will be paid a living wage. The tally was to have been conducted last Monday, but then another nor'easter struck, rendering the hardships of winter-without-shelter perhaps more vivid than most impersonators would have liked. The project was postponed a week.

Dr. Kim Hopper, a medical anthropologist at the Nathan Kline Institute and the former president of the National Coalition for the Homeless, is the architect of what the city is calling the Shadow Count, and the man in charge of implementing its "plant-capture" method: you plant a known quantity of itinerant decoys among the street population at large, and see how many of them you can spot in a night's worth of searching for actual homeless people; the percentage of decoys missed ought to resemble the percentage of the true population unaccounted for in your surveyors' ledgers. (When scientists tag a subset of elk with paintballs, and later attempt a recount from a helicopter, it's called "capture-recapture.")

Prospective decoys--Hopper wants a hundred and fifty--will be handed an instruction card shortly before heading out to assigned locations, at midnight, for three hours of role-playing. The card begins, "Your job is to pass for a homeless person on the street tonight. But you will be unusually stable, well-behaved, dressed for the weather, and approachable." As props, Hopper recommends bringing along only a blanket and "a crummy hat."

Booze? "Several people have asked if that's O.K.," Hopper said last week, in the midst of final preparations. "We had to develop some artful answer: 'You're employees of the research foundation for mental health; these are work hours for you and the usual rules apply.' But if people feel like misbehaving in a civil fashion on their own, I can't police them."

Reading material? Hopper's inclination was to say, "Yeah, whatever helps pass the time." But one of his students asked if he could bring his homelessness textbook along. "That's probably not the ...