.7% of all samples tested, and no significant differences in sensitivity or specificity were noted between HSCT and non-HSCT patients. IAs, while not as sensitive as direct fecal CBA, produce reasonable predictive values, especially when both antigen and toxin are detected. They also offer significant advantages over CBA in terms of turnaround time and ease of use.

A step-based tutoring system for linear circuit analysis is being developed with the capabilities to automatically generate circuit problems with specified characteristics, including randomly generated topologies and element values. The system further generates fully-worked, error-free solutions using the methods typically taught in such classes, and accepts a rich variety of student input such as equations, matrix equations, numerical and multiple-choice answers, re-drawn circuit diagrams, and sketches of waveforms. A randomized, controlled study was conducted using paid student volunteers to compare the effectiveness of two of our tutorials in comparison to working conventional textbook-based problems. The average learning gain was only 3/100 points for the textbook users, but 29/100 points, about 10 times higher, for the tutorial users. The effect size on the post-test scores was 1.21 pooled standard deviations (Cohen d-value) and was statistically significant. A motivational survey administered to these students yielded a 0.53 point higher rating for the software than for the textbook (on a 1-5 scale). The system is being used in Spring 2013 by over 340 students in EEE 202 at Arizona State and two community colleges. About 99% of these students rated the system as "very helpful" or "somewhat helpful."

A survey study was conducted to better understand how gameplay enjoyment relates to players’ personality traits and video game preferences. This study demonstrated that the core design elements of games that lead to enjoyment can be empirically identified. Similarly, it showed that considering personality, an individual characteristic, can produce informative insights about how players perceive gaming experiences. Whereas video game research has historically emphasized either games or players in isolation (Juul, 2010), this study is an initial effort towards a holistic approach that considers how design features and player characteristics combine to generate enjoyable video game experiences. Two empirical taxonomies for creating more enjoyable game experiences are presented.

To date, reviews of the games literature have noted a lack of empirical studies examining the relationships between games and their purported benefits (Huizenga, Admiraal, & Dam, 2011; Vandercruysse, Vanderwaetere, & Clarebout, 2012; Young et al., 2012). Furthermore, researchers have called for a better understanding of the specific game features that may lead to beneficial outcomes (Hartmann & Klimmt, 2006; Klimmt, Schmid, & Orthmann, 2009; McNamara, Jackson, & Graesser, 2010; Vorderer, Bryant, Pieper, & Weber, 2006; Wilson et al., 2009). In this survey study, a structural equation modeling (SEM) approach was employed to better understand the specific features that influence player enjoyment of video games. The resulting Gameplay Enjoyment Model (GEM) explains players’ overall Enjoyment of games, as well as their preferences for six specific types of enjoyment, including Challenge, Companionship, Competition, Exploration, Fantasy, and Fidelity. The implications of these model components are discussed in the context of educational game design and future directions for research are offered. GEM provides an empirical framework within which vital progress can be made in understanding the enjoyment of games and the role that games play in education.