Number of individual contacts per day, by source and day of the week. For each subject, the number of recorded contacts per day was determined. For each day of the week studied, we show the median number of contacts recorded in the paper diary, PDA diary and entry questionnaire (Pre Paper). Upper and lower bounds of the boxes reflect the interquartile range, whiskers define upper and lower adjacent values. We also report the mean value above each box plot. We report total contacts (a) and the number of unique names (b).