which particular relations to collect data. Relations among pairs of social actors have both form and content, a dichotomy that Georg Simmel (1908) proposed in his classic analyses of association. The two elements are empirically inseparable and only analytically distinguishable. Contents are the interests, purposes, drives, or motives of individuals in an interaction, whereas forms are modes of interaction through which specific contents attain social reality. Simmel argued that the task of sociology is to identify a limited number of forms—sociability, superiority, subordination, competition, conflict, cooperation, solidarity—that occur across a wide range of concrete settings, social institutions, and historical contexts. A particular form can vary greatly in content. For example, the basic forms of superordination and subordination are ever present in government, military, business, religious, athletic, and cultural institutions. Conversely, diverse contents like economic interests and drives for power are manifested through forms of competition and cooperation.
The form-content dichotomy also applies to social network analysis. Relational form is a property of relations that exists independently of any specific contents. Two fundamental relational forms are (a) the intensity, frequency, or strength of interaction between pairs of entities and (b) the direction of relations between both dyad members—null, asymmetric, or mutual choices. Relational content refers to its ‘‘substance as reason for occurring’’ (Burt, 1983, p. 36). Substantive content is an analytic construct designed by a researcher to capture the meanings of a relation from the informants’ subjective viewpoints. When people are asked, ‘‘please identify your close friends, friends, and acquaintances” in some social setting, the intended relational content is “friendship.” The results of this query depend on how each actor first conceptualizes the meanings of the three proffered response categories and then classifies the other actors according to recollections of diverse interpersonal interactions. Obviously, people may vary markedly in their interpretations of both the friendship labels and those activities that they consider to be indicators of greater or lesser intimacy. Friendship dyads are never precisely reciprocated and the level of intimacy may be very unequal; for example, one dyad member considers the second person a “best friend,” but the second member views the first person as a “friend.” The National Study of Adolescent Health (Add Health) found that girls and Asian Americans were most likely to have reciprocated friendships, whereas interracial friendships were much less common than friendships between students of the same race (Vaquera & Kao, 2008).
The choice of relational content, also called type of tie, is largely determined by a project’s theoretical concerns and research objectives. A study of healthcare networks could inquire into people’s interpersonal sources of trusted information and advice about health-related matters, whereas a project on political networks might ask them to identify others with whom they discussed or participated in political affairs. Some substantive problems imply that more than one analytically distinct relational content should be investigated, in which case measuring and simultaneously analyzing two or more types of ties (i.e., multiplex networks) is an appropriate strategy. For example, psychologists asked 132 undergraduates at Midwestern University to list their Facebook friends who fulfilled each of five social functions (i.e., types of ties): sharing social activities, discussing personal matters, providing instrumental support, providing emotional support, and sharing success and happy events (Gillath, Karantzas, & Selcuk, 2017). Students with higher attachment avoidance were likely to ascribe fewer multiplex social roles to their networks’ members, implying a lower degree of social trust.
Inexplicably, network analysts have conducted little research on the connections among diverse domains of relational contents. Ronald Burt (1983) examined survey respondents’ perceptions of relational contents and uncovered substantial confusion, redundancy, and substitutability among the 33 questions posed to a sample of Northern Californians. He concluded that just five key questions would suffice to recover the principal structure of relational contents in the friendship, acquaintance, work, kinship, and intimacy domains. However, we still need much more research on the similarities and differences of meanings that people attach to commonly used relational terms and labels in a wide variety of network settings. A cognitive map of the structural connections among relational content domains would enable researchers efficiently and accurately to select specific contents most relevant to their theoretical and substantive concerns.
Until that desideratum arrives, in the spirit of Simmel we propose a small typology of generic contents:
Transaction relations: Entities exchange control over physical or symbolic media, for example, in gift giving or economic sales and purchases.
Communication relations: Linkages between entities are channels through which messages may be transmitted.
Boundary penetration relations: Ties consist of membership in two or more social formations, for example, voluntary associations or social movement organizations.
Instrumental relations: Actors contact one another in efforts to obtain valued goods, services, or information, such as a job, an abortion, political favors, or religious salvation.
Sentiment relations: Perhaps the most frequently investigated networks involve actors expressing their feelings of affection, admiration, deference, loathing, or hostility toward one another.
Authority/power relations: These types of ties, usually occurring in formal hierarchical organizations, indicate the rights and obligations of position holders to issue and obey commands.
Kinship and descent relations: These bonds of blood and marriage reflect relations among family roles.
Levels of Analysis. After deciding the social setting and the relational forms and contents, researchers have several alternative levels at which to analyze the structures in data that they collect for social network projects. Details of appropriate measures and methods appear in Chapters 3 through 5, but here we summarize four conceptually distinct levels of analysis that analysts could investigate.
The simplest level is the egocentric network, consisting of one actor (ego) and all other actors (alters) with which ego has direct relations as well as the direct relations among those alters. This set is also called ego’s ‘‘first zone,’’ in contrast to second and higher zones consisting of all the alters of ego’s alters, and so on. If a network’s size is N actors, an egocentric analysis would have N units of analysis. Each ego actor can, in turn, be described by the number, intensity, and other characteristics of its linkages with its set of alters, for example, the proportion of reciprocated relations or the density of ties among its alters. An egocentric analysis of incarcerated California youths indicated that respondents reporting no close friendships within the facility had lower postinterview misconduct than those who nominated peers, suggesting an influence or amplifying effect of friends on misbehavior (Reid, 2017). In some respects, egocentric analysis resembles typical attribute-based survey research, with a respondent’s individual characteristics such as gender, age, and education supplemented by measures derived from that person’s direct network relations. Egocentric network research designs are well suited to surveys of respondents who are unlikely to have any contact with one another. The 1985 General Social Survey of the adult U.S. population (Marsden, 1987) pioneered procedures for identifying and eliciting information about a respondent’s alters, which we describe in some detail in Chapter 3.
A second level of analysis is the dyadic network, consisting of pairs of actors. If the order of a pair is irrelevant—as in marital status where persons are either unmarried, cohabiting, married, separated, or divorced—a sample of N actors has (N2 – N)/2 dyadic units of analysis. But, if the direction of a relation matters, as in
