Estimating household water use: A comparison of diary, prompted recall, and free recall methods

Studies of household water use are often based on retrospective behavioral reports, which are vulnerable to threats to informant accuracy. This article compares three methods for collecting household water use data: a diary, prompted recall, and free recall. The analyses are based on data from seventy-two randomly selected households in Cochabamba, Bolivia. Per capita water use estimates based on the three methods were significantly different. When compared against known parameters, the diary provided the most accurate estimate of household water use. The prompted recall method yielded similar results to the diary method on hygienic and food preparation tasks, but there were significant differences on household cleaning tasks. The free recall method significantly underestimated water use. There were not significant differences in water use assessments within households, but there was variation in misestimation across households. The article discusses which participants (e.g., heads of less water-consumptive households) provided more reliable water use estimates.