Community of inquiry as a theoretical framework to foster “epistemic engagement” and “cognitive presence” in online education

In this paper, several recent theoretical conceptions of technology-mediated education are examined and a study of 2159 online learners is presented. The study validates an instrument designed to measure teaching, social, and cognitive presence indicative of a community of learners within the community of inquiry (CoI) framework [Garrison, D. R., Anderson, T., & Archer, W. (2000). Critical inquiry in a text-based environment: Computer conferencing in higher education. The Internet and Higher Education, 2, 1–19; Garrison, D. R., Anderson, T., & Archer, W. (2001). Critical thinking, cognitive presence, and computer conferencing in distance education. American Journal of Distance Education, 15(1), 7–23]. Results indicate that the survey items cohere into interpretable factors that represent the intended constructs. Further it was determined through structural equation modeling that 70% of the variance in the online students’ levels of cognitive presence, a multivariate measure of learning, can be modeled based on their reports of their instructors’ skills in fostering teaching presence and their own abilities to establish a sense of social presence. Additional analysis identifies more details of the relationship between learner understandings of teaching and social presence and its impact on their cognitive presence. Implications for online teaching, policy, and faculty development are discussed.     

Optical probe measurements of the temperature of burning particles in fluidized beds

The temperatures of freely moving petroleum coke particles burning in the interior of a fluidized bed of sand have been measured. An optical probe technique, employing two-wavelength pyrometry with wavelengths centred at 800 and 1000 nm, was used for the measurements over a wide range of operating conditions. Measurements were conducted in bubbling fluidized beds of 1.82 × 10⁻⁴ m and 1.09 × 10⁻³m sand particles maintained at bed temperatures of 973 and 1200 K. Batches of petroleum coke particles having average diameters in the range 7.5 × 10⁻⁴ to 8.1 × 10⁻³ m were charged into the hot fluidized bed combustor, and upon the passage of a burning particle across the optical probe's field of view, a pulsed signal was generated. Signals from the interior of the bed were continuously monitored by a pair of radiometers interfaced to a high speed data acquisition system and were processed off-line for particle temperature calculations. The average particle temperatures exceeded the bed temperature by 60–360 K for the operating conditions considered. It was found that particle temperatures in the bubble phase were on average, higher than in the emulsion phase. Further, the temperatures of particles were lower closer to the distributor as a consequence of particle circulation and combustion-assisted attrition within the bed.     

Learning presence as a moderator in the community of inquiry model

This study of over 2000 US college students examines the Community of Inquiry framework (CoI) in its capacity to describe and explain differences in learning outcomes in hybrid and fully online learning environments. We hypothesize that the CoI model's theoretical constructs of presence reflect educational effectiveness in a variety of environments, and that online learner self-regulation, a construct that we label “learning presence” moderates relationships of the other components within the CoI model. Consistent with previous research (e.g., Means, Toyama, Murphy, Bakia, & Jones, 2009; Shea & Bidjerano, 2011) we found evidence that students in online and blended courses rank the modalities differently with regard to quality of teaching, social, and cognitive presence. Differences in help seeking behavior, an important component of self-regulated learning, were found as well. In addition, results suggest teaching presence and social presence have a differential effect on cognitive presence, depending upon learner's online self-regulatory cognitions and behaviors, i.e. their learning presence. These results also suggest a compensation effect in which greater self-regulation is required to attain cognitive presence in the absence of sufficient teaching and social presence. Recommendations for future research and practice are included.