Some solvers, such as lingeling, use techniques The SAT Competitions, organized since 2002, have been the that cannot be expressed using resolution and cannot driving force of SAT solver development. The performance be expressed in the SAT Competition 2013 formats. of contemporary SAT solvers is incomparable to those of a One technique that cannot be expressed using resolution, decade ago. As a consequence, SAT solvers are used as the but is used in some top solvers, is bounded variable addition core search engine in many utilities, including tools for hardware (Manthey, Heule, and Biere 2013).

Answer Set Programming (ASP) is a well-established paradigm of declarative programming that has been developed in the field of logic programming and nonmonotonic reasoning. Advances in ASP solving technology are customarily assessed in competition events, as it happens for other closely-related problem-solving technologies like SAT/SMT, QBF, Planning and Scheduling. ASP Competitions are (usually) biennial events; however, the Fifth ASP Competition departs from tradition, in order to join the FLoC Olympic Games at the Vienna Summer of Logic 2014, which is expected to be the largest event in the history of logic. This edition of the ASP Competition series is jointly organized by the University of Calabria (Italy), the Aalto University (Finland), and the University of Genova (Italy), and is affiliated with the 30th International Conference on Logic Programming (ICLP 2014). It features a completely re-designed setup, with novelties involving the design of tracks, the scoring schema, and the adherence to a fixed modeling language in order to push the adoption of the ASP-Core-2 standard. Benchmark domains are taken from past editions, and best system packages submitted in 2013 are compared with new versions and solvers. To appear in Theory and Practice of Logic Programming (TPLP).

Answer Set Programming (ASP) is a well-established paradigm of declarative programming in close relationship with other declarative formalisms such as SAT Modulo Theories, Constraint Handling Rules, FO(.), PDDL and many others. Since its first informal editions, ASP systems have been compared in the now well-established ASP Competition. The Third (Open) ASP Competition, as the sequel to the ASP Competitions Series held at the University of Potsdam in Germany (2006-2007) and at the University of Leuven in Belgium in 2009, took place at the University of Calabria (Italy) in the first half of 2011. Participants competed on a pre-selected collection of benchmark problems, taken from a variety of domains as well as real world applications. The Competition ran on two tracks: the Model and Solve (M&S) Track, based on an open problem encoding, and open language, and open to any kind of system based on a declarative specification paradigm; and the System Track, run on the basis of fixed, public problem encodings, written in a standard ASP language. This paper discusses the format of the Competition and the rationale behind it, then reports the results for both tracks. Comparison with the second ASP competition and state-of-the-art solutions for some of the benchmark domains is eventually discussed. To appear in Theory and Practice of Logic Programming (TPLP).

Researchers in the field of intelligent tutoring systems (ITS) seek to create computerized tutors that can rival the learning gains produced by human tutoring, the most effective form of instruction known. The goal of the researchers is to produce ITS that provide flexible, efficient, individualized instruction to every student. Pursuit of this common goal has led them to examine many different aspects of how students learn from tutors, how human tutors interact with their students, and how students learn in collaborative environments. Insights from those studies have informed further research into ways that computer systems can detect and respond to student knowledge gaps, misconceptions, affective states and other attributes. This research has produced important work in student modeling, knowledge representation, dialog systems, and authoring tools for efficiently creating ITS in new domains.