David Krackhardt

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An analysis is conducted on the robustness of measures of centrality in the face of random error in the network data. We use random networks of varying sizes and densities and subject them (separately) to four kinds of random error in varying amounts. The types of error are edge deletion, node deletion, edge addition, and node addition. The results show(More)
MRQAP (Multiple Regression – Quadratic Assignment Procedure) tests are permutation tests for multiple regression coefficients for data organized in square matrices instead of vectors. Such a data structure is typical in social network studies, where variables indicate some type of relation between a given set of actors. Over the last 15 years, new(More)
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In this article, we study the conditions under which having ties that span organizational boundaries (bridging ties) are conducive to the generation of innovations. Whereas previous research has shown that bridging ties have a positive impact on innovative performance, our analysis of 276 R&D scientists and engineers reveals that there are no advantages(More)
This study explores one of the contributors to group composition – the basis on which people choose others with whom they want to work. We use a combined model to explore individual attributes, relational attributes, and previous structural ties as determinants of work partner choice. Four years of data from participants in 33 small project groups were(More)
The spatial arrangement of social network data in graphs can influence viewers" perceptions of structural characteristics such as prominence, bridging and grouping. To study the extent of this effect, we conducted an experiment with 80 graduate students. Each student viewed three of five different spatial arrangements of the same network. We found that(More)
OBJECTIVE To study how social interactions influence physician adoption of an electronic health records (EHR) system. DESIGN A social network survey was used to delineate the structure of social interactions among 40 residents and 15 attending physicians in an ambulatory primary care practice. Social network analysis was then applied to relate the(More)