Anuška Ferligoj

Generalized blockmodeling of two-mode network data

Abstract We extend the direct approach for blockmodeling one-mode data to two-mode data. The key idea in this development is that the rows and columns are partitioned simultaneously but in different ways. Many (but not all) of the generalized block types can be mobilized in blockmodeling two-mode network data. These methods were applied to some ‘voting’ data from the 2000–2001 term of the Supreme Court and to the classic Deep South data on women attending events. The obtained partitions are easy to interpret and compelling. The insight that rows and columns can be partitioned in different ways can be applied also to one-mode data. This is illustrated by a partition of a journal-to-journal citation network where journals are viewed simultaneously as both producers and consumers of scientific knowledge.

Direct and indirect methods for structural equivalence

Abstract Procedures for establishing a partition of a network in terms of structural equivalence can be divided into direct and indirect approaches. For the former, a new criterion function is proposed that reflects directly structural equivalence concerns. This criterion function can then be (locally) optimized to create a partition. For indirect approaches, measures of dissimilarity must be compatible with the definition of structural equivalence.

An optimizational approach to regular equivalence

Abstract Most partitions of social network (relational) data are presented and interpreted with little attention to assessing the adequacy of the partitions. We present a new criterion function that operationalizes the concept of regular equivalence and provides a measure of the departure of any structure from an exact regular partition. We then use a local optimization procedure to locate partitions where the algorithm minimizes the criterion function. After applying these methods for constructed and empirical data sets, we compare our results with those obtained from using other methods.

Evaluation of social network measurement instruments

Abstract This paper evaluates the reliability and validity of network measurement instruments for measuring social support. The authors present and discuss the results from eight experiments which were designed to analyze the quality of four measurement scales: (1) binary, (2) categorical, (3) categorical with labels, and (4) line production, as well as two measurement techniques for listing alters (free recall and recognition). Reliability and validity were estimated by the true score multitrait–multimethod (MTMM) approach. Meta-analysis of factors affecting the reliability and the validity of network measurement was done by multiple classification analysis (MCA). The results show that the binary scale and the first presentation of measurement instruments are the least reliable. Surprisingly, the two data collection techniques (free recall and recognition) yield equally reliable data.

Clustering with relational constraint

The paper deals with clustering problems where grouping is constrained by a symmetric and reflexive relation. For solving clustering problems with relational constraints two methods are adapted: the “standard” hierarchical clustering procedure based on the Lance and Williams formula, and local optimization procedure, CLUDIA. To illustrate these procedures, clusterings of the European countries are given based on the developmental indicators where the relation is determined by the geographical neighbourhoods of countries.

Estimating the reliability and validity of personal support measures: full information ML estimation with planned incomplete data

Egocentered networks are common in social science research. Here, the unit of analysis is a respondent (ego) together with his/her personal network (alters). Usually, several variables are used to describe the relationship between egos and alters. In this paper, the aim is to estimate the reliability and validity of the averages of these measures by the multitrait–multimethod (MTMM) approach. This approach usually requires at least three repeated measurements (methods) of the same variable (trait) for model identification. This places a considerable burden on the respondent and increases the cost of data collection. In this paper, we use a split ballot MTMM experimental design, proposed by Saris (1999), in which separate groups of respondents get different combinations of just two methods. The design can also be regarded as having a planned missing data structure. The maximum likelihood estimation is used in the manner suggested by Allison (1987) of a confirmatory factor analysis model for MTMM-designs specified in Saris and Andrews (1991). This procedure is applied to social support data collected in the city of Ljubljana (Slovenia) in the year 2000.

Collaboration structures in Slovenian scientific communities

We combine two seemingly distinct perspectives regarding the modeling of network dynamics. One perspective is found in the work of physicists and mathematicians who formally introduced the small world model and the mechanism of preferential attachment. The other perspective is sociological and focuses on the process of cumulative advantage and considers the agency of individual actors in a network. We test hypotheses, based on work drawn from these perspectives, regarding the structure and dynamics of scientific collaboration networks. The data we use are for four scientific disciplines in the Slovene system of science. The results deal with the overall topology of these networks and specific processes that generate them. The two perspectives can be joined to mutual benefit. Within this combined approach, the presence of small-world structures was confirmed. However preferential attachment is far more complex than advocates of a single autonomous mechanism claim.

Effects on reliability and validity of egocentered network measurements

Abstract This paper examines the reliability and validity of egocentered networks. Reliability and validity are estimated by the multitrait-multimethod (MTMM) approach. A split ballot MTMM design [Saris, W.E., 1999. Forced choice or agree/disagree questions? An evaluation by the split ballot MTMM experiment. In: Proceeding of the Meeting of the IRMCS, pp. 122–146; Kogovsek, T., Ferligoj, A., Coenders, G. Saris, W. E., 2002. Estimating the reliability and validity of personal support measures: full information ml estimation with planned incomplete data. Social Networks 24, 1–20] is used, in which separate groups of respondents received different combinations of two methods. The effect of factors such as the methods used and the personal characteristics of respondents that can affect the quality of data was estimated by a meta analysis. Measurement method, type of question, network size, age, gender, extraversion and emotional stability all had statistically significant effects on the validity of measurement. After the list of alters is obtained with name generators, name interpreter questions can be asked in two ways. One way (“by alters”) is to take each alter individually and to ask all the questions about him/her, going alter by alter until the end of the list of alters. The other way (“by questions”) is to take the question and ask this question for all alters on the list, going question by question until the end of the list of name interpreter questions. Telephone interviewing (both by alters and by questions) gave more valid measurements than face-to-face interviews. Behavioral questions were more valid than questions with emotional content. The characteristics of ties were more validly measured in smaller networks. With reference to respondents’ personal characteristics younger respondents, men, extraverted and emotionally stable respondents all had more valid measurements. Reliability was significantly affected by the measurement method, the type of question and age. The telephone/by alters method was the most reliable measurement method. Behavioral questions were more reliable than questions with emotional content. Measurements among younger respondents were also more reliable.

Gender-Role Attitudes in University Students in the United States, Slovenia, and Croatia

Determinants of gender-role attitudes were examined in samples of university students from Pittsburgh in the United States, Ljubljana in Slovenia, and Osijek in Croatia. Surveys including items from the Attitudes Toward Women Scale and the Neosexism Scale were administered to a total of 1,544 U.S. students, 912 Slovene students, and 996 Croatian students between the years of 1991 and 2000. As predicted, men held less egalitarian or more sexist attitudes about the appropriate roles for women and men, and those with more frequent attendance at religious services held more sexist attitudes. No changes in attitudes were found for women over time, but Slovene males were found to become more traditional over time.

Achievement, Power, and Affiliation Motives as Clues to (E)migration Desires: A Four-Countries Comparison

Within the framework of McClelland’s motivational theory, a model of the motivational structure of the migrant personality is proposed. It is argued that those who choose to leave their country of origin have higher achievement and power motivation and lower affiliation motivation than those who want to stay. This model was tested with 1050 college students in Albania, the Czech Republic, and Slovenia. Data were collected between 1993 and 1996. MANOVA analysis confirmed our predictions for the achievement and power motives. Students who wanted to emigrate had higher achievement and power motivation scores than those who wanted to stay. This model was also applied to internal migrants. It was tested with 789 United States college students. Those who wanted to leave the region of their university after graduation scored significantly higher on achievement and power motivation than those who wanted to stay. It is argued that this pattern is specific for countries or regions of economic stagnation or decline,...