Decimal Point: A Decade of Learning Science Findings with a Digital Learning Game

The McLearn Lab at Carnegie Mellon University (CMU) first designed and developed the artificial intelligenceArtificial Intelligence (AI) in education learning game, Decimal Point, in 2013 and 2014 to support middle school children learning decimals and decimal operations. Over a period of 10 years, the McLearn Lab has run a series of classroom experiments with the game, involving over 1,500 elementary and middle school students. In these studies, we have explored a variety of game-based learning and learning science principles and issues, such as whether the game leads to better learning—demonstrated learning gains from a pretest to a posttest and/or a delayed posttest—than a more traditional online instructional approach; whether giving students more agency leads to more learning and enjoyment; whether students benefit from hints and error messages provided during game play; and what types of prompted self-explanation lead to the best learning and enjoyment outcomes. A fascinating finding also emerged during the variety of experiments we conducted: the game consistently led to a gender effect in which girls learned more from the game than boys. In this chapter I will discuss the current state of digital learning gamesDigital learning games, how we designed and developed Decimal Point, the technology it is built upon—including AI techniques—and the key results of the various experiments we’ve conducted over the years. I conclude by discussing the important game-based learning take-aways from our studies, what we have learned about using a digital learning gameDigital learning games as a research platformResearch platform for exploring learning science principles and issues; and exciting future directions for this line of research.