Forgetting of friends and its effects on measuring friendship networks

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 hall as they could. Then, on a complete list of hall residents, residents indicated 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 recalled correlates moderately positively with the number of friends forgotten. Recalled and forgotten friends do not differ appreciably in terms of their individual characteristics, although residents on average had modestly closer relationships with recalled friends than forgotten friends. Forgetting also influenced the measurement of some social network structural properties, such as density, number of cliques, centralization, and individuals' centralities. More research is required to determine whether forgetting distorts measurement of structural properties in other settings. (C) 1999 Elsevier Science B.V. All rights reserved.