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Confirmatory Blockmodeling
Confirmatory blockmodeling is a deductive analysis, deductive approach in blockmodeling, where a blockmodel (or part of it) is prespecify before the analysis, and then the analysis is fit to this model. When only a part of analysis is prespecify (like individual cluster(s) or location of the block types), it is called ''partially confirmatory blockmodeling''. This is so-called indirect approach, where the blockmodeling is done on the blockmodel fitting (e.g., ''a priori'' hypothesized blockmodel).Aleš Žiberna, ''Generalized blockmodeling of valued networks (pospološeno bločno modeliranje omrežij z vrednostmi na povezavah: doktorska disertacija''. Ljubljana: Univerza v Ljubljani, Fakulteta za družbene vede, 2007. URL: http://www2.arnes.si/~aziber4/blockmodeling/Dissertation-final-corrected.pdf. Opposite approach to the confirmatory blockmodeling is an inductive analysis, inductive exploratory blockmodeling. References {{reflist See also * prespecific blockmodeling B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deductive Analysis
In mathematical logic, a deduction theorem is a metatheorem that justifies doing conditional proofs—to prove an implication ''A'' → ''B'', assume ''A'' as an hypothesis and then proceed to derive ''B''—in systems that do not have an explicit inference rule for this. Deduction theorems exist for both propositional logic and first-order logic. The deduction theorem is an important tool in Hilbert-style deduction systems because it permits one to write more comprehensible and usually much shorter proofs than would be possible without it. In certain other formal proof systems the same conveniency is provided by an explicit inference rule; for example natural deduction calls it implication introduction. In more detail, the propositional logic deduction theorem states that if a formula B is deducible from a set of assumptions \Delta \cup \ then the implication A \to B is deducible from \Delta ; in symbols, \Delta \cup \ \vdash B implies \Delta \vdash A \to B . In the spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blockmodeling
Blockmodeling is a set or a coherent framework, that is used for analyzing social structure and also for setting procedure(s) for partitioning (clustering) social network's units (nodes, vertices, actors), based on specific patterns, which form a distinctive structure through interconnectivity.Patrick Doreian, An Intuitive Introduction to Blockmodeling with Examples, ''BMS: Bulletin of Sociological Methodology'' / ''Bulletin de Méthodologie Sociologique'', January, 1999, No. 61 (January, 1999), pp. 5–34. It is primarily used in statistics, machine learning and network science. As an empirical procedure, blockmodeling assumes that all the units in a specific network can be grouped together to such extent to which they are equivalent. Regarding equivalency, it can be structural, regular or generalized.Anuška Ferligoj: Blockmodeling, http://mrvar.fdv.uni-lj.si/sola/info4/nusa/doc/blockmodeling-2.pdf Using blockmodeling, a network can be analyzed using newly created blockmodels, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blockmodel
Blockmodel (sometimes also block model) in blockmodeling (part of network science) is defined as a multitude of structures, which are obtained with: * identification of all vertices (e.g., units, nodes) within a cluster and at the same time representing each cluster as a vertex, from which vertices for another graph can be constructed; * combination of all the links (ties), represented in a block as a single link between positions, while at the same time constructing one tie for each block. In a case, when there are no ties in a block, there will be no ties between the two positions, that define the block. In principle, blockmodeling, as a process, is composed from three steps. In the first step, the number of units is determined. This is followed (in the second step) by selection or determination of permitted blocks, that will occur and perhaps also the locations in the matrix. The last, third step, using computer program, the partitioning of units is done, according to the pre- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aleš Žiberna
Aleš Žiberna is a Slovene statistician, whose specialty is network analysis. His specific research interests include blockmodeling, multivariate analysis and computer intensive methods (e.g., computer simulations, resampling methods). Currently, he is employed at the Faculty of Social Sciences of the University of Ljubljana, specifically at the Chair of Social Informatics and Methodology, and Centre for Methodology and Informatics. Work In 2007, he proposed a solution to the generalized valued blockmodeling by introducing homogeneity blockmodeling with the basic idea "that the inconsistency of an empirical block with its ideal block can be measured by within block variability of appropriate values". The newly-formed ideal blocks, which are appropriate for blockmodeling of valued networks, are then presented together with the definitions of their block inconsistencies. He also (in 2007/08) developed an implicit blockmodeling approach, based on previous work of Batagel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inductive Analysis
Mathematical induction is a method for proving that a statement ''P''(''n'') is true for every natural number ''n'', that is, that the infinitely many cases ''P''(0), ''P''(1), ''P''(2), ''P''(3), ... all hold. Informal metaphors help to explain this technique, such as falling dominoes or climbing a ladder: A proof by induction consists of two cases. The first, the base case, proves the statement for ''n'' = 0 without assuming any knowledge of other cases. The second case, the induction step, proves that ''if'' the statement holds for any given case ''n'' = ''k'', ''then'' it must also hold for the next case ''n'' = ''k'' + 1. These two steps establish that the statement holds for every natural number ''n''. The base case does not necessarily begin with ''n'' = 0, but often with ''n'' = 1, and possibly with any fixed natural number ''n'' = ''N'', establishing the truth of the statement for all nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
