>For example, the number of calls to the city’s “311” complaint hotline was considered to indicate which buildings were most in need of attention. More calls equaled more serious problems. But this turned out to be a misleading measure. A rat spotted on the posh Upper East Side might generate 30 calls within an hour, but it might take a battalion of rodents before residents in the Bronx felt moved to dial 311. Likewise, the majority of complaints about an illegal conversion might be about noise, not about hazardous conditions.