We assessed the forgetting of friends and its effects on measuring personal
and social network characteristics and properties. All 217 residents of a
university residence hall first recalled as many of their friends in the ha
ll as they could. Then, on a complete list of hall residents, residents ind
icated other friends they forgot to recall. On average, residents forgot 20
% of their friends. Residents' demographic characteristics are unrelated to
the proportion of friends forgotten. However, the number of friends recall
ed correlates moderately positively with the number of friends forgotten. R
ecalled and forgotten friends do not differ appreciably in terms of their i
ndividual characteristics, although residents on average had modestly close
r relationships with recalled friends than forgotten friends. Forgetting al
so influenced the measurement of some social network structural properties,
such as density, number of cliques, centralization, and individuals' centr
alities. More research is required to determine whether forgetting distorts
measurement of structural properties in other settings. (C) 1999 Elsevier
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