In a study of birth planning in China, Greenhalgh (in Ryan and Bernard, 2003) surveyed 1,011 ever-married women, gathered social and economic histories from 150 families. She conducted in-depth interviews with present and formal officials (known as cadres), and collected documentary evidence from local newspapers, journals and other sources. Greenhalgh notes that "Because I was largely constrained from asking direct questions about resistance, the informal record of field notes, interview transcripts, and questionnaire data contains few overt challenges to state policy." Greenhalgh concludes, however, that their conversations with the researchers, both peasants and cadres made strategic use of silence to protest aspects of the policy they did not like. Cadres, for example were loathe to comment on birth-planning campaigns; peasant women were reluctant to talk about sterilization. These silences form one part of the unofficial record of birth planning in the villages. More explicit protests were registered in informal conversations. From these interactions emerged a sense of profound distress of villagers forced to choose between a resistance that was politically risky and a compliance that violated the norms of Chinese culture and of practical reason.