Learning sciences (LS) is an interdisciplinary field that works to further scientific, humanistic and critical theoretical understanding of learning as well as to engage in the design and implementation of learning innovations, and the improvement of instructional methodologies. Research in the learning sciences traditionally focuses on cognitive-psychological, social-psychological, cultural-psychological and critical theoretical foundations of human learning, as well as on the design of learning environments. Major contributing fields include cognitive science, computer science, educational psychology, anthropology, and applied linguistics. Over the past decade, researchers have also expanded their focus to the design of curricula, informal learning environments, instructional methods, and policy innovations. Learning sciences (LS) is an interdisciplinary field that works to further scientific, humanistic and critical theoretical understanding of learning as well as to engage in the design and implementation of learning innovations, and the improvement of instructional methodologies. Research in the learning sciences traditionally focuses on cognitive-psychological, social-psychological, cultural-psychological and critical theoretical foundations of human learning, as well as on the design of learning environments. Major contributing fields include cognitive science, computer science, educational psychology, anthropology, and applied linguistics. Over the past decade, researchers have also expanded their focus to the design of curricula, informal learning environments, instructional methods, and policy innovations. As an emerging discipline, the learning sciences are still in the process of defining itself. Accordingly, the identity of the field is multifaceted, and varies from institution to institution. However, the International Society of Learning Sciences (ISLS, ) summarizes the field as follows: 'Researchers in the interdisciplinary field of learning sciences, born during the 1990s, study learning as it happens in real-world situations and how to better facilitate learning in designed environments – in school, online, in the workplace, at home, and in informal environments. Learning sciences research may be guided by constructivist, social-constructivist, socio-cognitive, and socio-cultural theories of learning.' ISLS has a large worldwide membership, is affiliated with two international journals: Journal of the Learning Sciences, and International Journal of Computer Supported Collaborative Learning, and sponsors the biennial Computer Supported Collaborative Learning conference and International Conference of the Learning Sciences on alternate years. Although controlled experimental studies and rigorous qualitative research have long been employed in learning sciences, LS researchers often use design-based research methods. Interventions are conceptualized and then implemented in natural settings in order to test the ecological validity of dominant theory and to develop new theories and frameworks for conceptualizing learning, instruction, design processes, and educational reform. LS research strives to generate principles of practice beyond the particular features of an educational innovation in order to solve real educational problems, giving LS its interventionist character. Several significant events have contributed to the international development of learning sciences. Perhaps the earliest history can be traced back to the cognitive revolution. In the United States, an important effort to create a graduate program in learning sciences took place in 1983 when Jan Hawkins and Roy Pea proposed a joint program between Bank Street College and the New School for Social Research. Called 'Psychology, Education, and Technology' (PET), the program had a planning grant supported by the Sloan Foundation. In the end the program would have required new faculty, though, and the institutions involved never established such a program. Roger Schank's arrival at Northwestern University in 1988 helped start the Institute for Learning Sciences. In 1991, Northwestern initiated the first learning sciences doctoral program, designed by and launched by Roy Pea as its first director. The program began accepting students in 1992, and after Pea became dean the program directorship was taken over by Brian Reiser. Since that time, a number of other high quality graduate programs in learning sciences began to appear around the world, and the field is continuing to be recognized as an innovative and influential area for education research and design. The Journal of the Learning Sciences was first published in 1991, with Janet Kolodner as founding editor. Yasmin Kafai and Cindy Hmelo-Silver took over as editors in 2009, and then Iris Tabak and Joshua Radinsky took over as editors in 2013. The International Journal of Computer-Supported Collaborative Learning was established as a separate journal in 2006, edited by Gerry Stahl and Freiderich Hesse. These journals, while relatively new in the field of education research, rapidly escalated and continue to place in upper ranks of the Educational Research section of the Social Sciences Citation Index impact factor rankings. The Institute for the Learning Sciences hosted the first International Conference for the Learning Sciences (ICLS) in August 1991 at Northwestern University (edited by Lawrence Birnbaum, and published by the AACE but no longer available). The first biennial meeting of the ICLS also took place at Northwestern University, in 1994. The International Society of the Learning Sciences was established in 2002. By integrating multiple fields, learning sciences extends beyond other closely related fields in distinguishable ways. For example, learning sciences extends beyond psychology, in that it also accounts for, as well as contributes to computational, sociological and anthropological approaches to the study of learning. Similarly, learning sciences draws inspiration from cognitive science, and is regarded as a branch of cognitive science; however, it gives particular attention to improving education through the study, modification, and creation of new technologies and learning environments, and various interacting and emergent factors that potentially influence the learning of humans. Many learning sciences researchers employ design-based research methodology. The growing acceptance of design-based research methodology as a means for study is often viewed as a significant factor distinguishing learning sciences from many of the fields that contribute to it. By including design-based research within its methodological toolkit, learning sciences qualifies as a 'design science', with characteristics in common with other design sciences that employ design science such as engineering and computer science. Learning sciences is also considered by some as having some degree of overlap with instructional design, although historically the two communities have come about in different ways and at times emphasized different programs of research, as described in a special issue of the journal Educational Technology in 2004.