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Inverse frequent itemset mining can be successfully modelled as an instance of the Probabilistic Satisfiability problem. Given a transaction database we can perform a frequent itemset mining algorithm, like the Apriori algorithm, to obtain useful itemset collections such as frequent or closed itemsets. We then use these itemset collections as frequency constraints in order to reconstruct the original database by solving a linear programming problem. There are cases however, where the reconstructed database is not in direct agreement with the original one. In this study, we analyse the degree of similarity between the original database and the reconstructed one, when different variations of condensed itemset representations are used as the initial frequency constraints. We examine how much the initial database properties and itemset relations have been preserved when we emphasize on the frequent itemset border and assess database quality by measuring database distance metrics. As this solution framework presents increased computational cost, we also consider a heuristic approach that is based on the notion that a transaction can be also considered as an itemset and compare the strengths and weaknesses of each framework when the same conditions apply. We manage to improve the efficiency of existing heuristic based approaches to the problem by utilizing smaller initial itemset collections. Our work contributes in (a) privacy preserving data mining and (b) gain in transaction database storage memory savings. [ABSTRACT FROM AUTHOR]

This paper introduces a new theoretical scheme for the solution of the frequent itemset hiding problem. We propose an algorithmic approach that consists of a novel constraint-based hiding model which encompasses hiding into one pass mining, along with a solution methodology that relies on Linear Programming. The induced patterns by the constraint-based mining algorithm are, in this way, utilized to build a minimal linear program whose solution dictates the construction of a database extension that delivers the sought-for hiding. This extension should be appended to the original database and released as a whole for mining, with that resulting extended database hiding the sensitive knowledge that we want to protect. Our proposed theory outdoes both in space complexity and accuracy, all the existing approaches which have been proposed so far in this domain and we proved that superiority with a series of experiments against other existing approaches. Our proposal sheds a new light on the exploration of new algorithmic techniques which can be handily applied to model hiding problems by providing solutions that computationally outperform all existing modeling approaches for hiding. [ABSTRACT FROM AUTHOR]

Educational Data Mining has turned into an effective technique for revealing relationships hidden in educational data and predicting students' learning outcomes. One can analyze data extracted from the students' activity, educational and social behavior, and academic background. The outcomes which are produced are, the following: A personalized learning procedure, a feasible engagement with students' behavior, a predictable interaction of the students with the learning processes and data. In the current work, we apply several supervised methods aiming at predicting the students' academic performance. We prove that the use of the default parameters of learning algorithms on a voting generalization procedure of the three most accurate classifiers, can produce better results than any single tuned learning algorithm. [ABSTRACT FROM AUTHOR]