Peer Support to Facilitate Knowledge Sharing on Complex Tasks

This thesis explores how to design a peer support system to facilitate self-organized knowledge sharing in non-formal learning environments, in particular when learners work on complex tasks. The peer support system aims to replace two teacher-led didactic arrangements: selecting a tutor at the initial stage, and guidance during the interaction process (Dillenbourg, 1999; Topping, 1996). Such a system has previously been developed by Van Rosmalen (2008) and De Bakker (2010) and has been tentatively used to facilitate knowledge sharing on content-related questions. In this thesis, we would like to find out how to further improve the design of this peer support system, especially to facilitate knowledge sharing on complex tasks. Since little pedagogical theory is available to inform the design of our peer support system, this thesis attempts to apply cognitive load theory (Sweller, Van Merriënboer, & Paas, 1998; Van Merriënboer & Sweller, 2005) that informs instructional designs in classroom settings to the design of our peer support system in Learning Networks

Designing optimal peer support to alleviate learner cognitive load in Learning Networks

In Learning Networks, learners have to engage in social interactions for sharing knowledge to achieve their personalized learning goals. When working on complex tasks, self-organized knowledge sharing imposes too much cognitive load and this is detrimental to learning. According to pedagogical guidelines of cognitive load theory, learning environments should not only avoid activities that distract learner attention but also focus learner attention on relevant activities that contribute to learning. This paper applied these guidelines in two studies, both meant to explore how to design an optimal peer support system. Study 1 aimed to alleviate learner cognitive load by using an automated peer tutor selection system. However, the results could not support our assumption that finding available peers for those who need knowledge sharing alleviates learner cognitive load. Study 2 explored how to support the interaction process of knowledge sharing by enhancing different competencies, namely content knowledge and tutoring skills. The results showed that supporting learners with different competencies alleviates cognitive load on different dimensions. Interestingly, students supported with content knowledge felt significantly more frustrated than those with tutoring skills. Our future research aims to design an optimal peer support system by 1) alleviating learner cognitive load through refining selection criteria to find suitable peers for knowledge sharing and 2) optimizing interaction process by designing support structures based on content knowledge and tutoring skills during knowledge sharing

Cognitive load and knowledge sharing in Learning Networks

Learning Networks are online social networks designed to support non-formal learning; they are therefore particularly suitable for self-directed learners. In Learning Networks, learners need to acquire knowledge through knowledge sharing with other participants. However, without a support structure, learners have to organize knowledge sharing themselves and this could induce extraneous cognitive load. When working on complex learning tasks, this organizing process could have a detrimental effect on knowledge acquisition. To optimize cognitive load, we propose to use a particular type of collaborative learning, peer tutoring, as a support structure. Its mechanisms reduce, we argue, the extraneous load imposed by organizing knowledge sharing as well as induce germane load by directing the freed cognitive capacity to processes that contribute to knowledge acquisition

Effects of training peer tutors in content knowledge versus tutoring skills on giving feedback to help tutees’ complex tasks

This study aims to investigate the effectiveness of training tutors in content knowledge of a particular domain versus training them in tutoring skills of pedagogical knowledge when tutoring on a complex tutee task. Forty-seven tutor-tutee pairs of fourth year secondary school students were created and assigned to one of two treatments. Twenty-two tutors received training in content knowledge and the other twenty-five tutors in tutoring skills. Tutors formulated written feedback immediately after the training. Tutees first interpreted the tutor feedback and then used it to revise their research questions. The results showed that tutors trained in tutoring skills formulated more effective feedback than tutors trained in content knowledge. In addition, tutees helped by tutoring-skills tutors found the feedback more motivating than those helped by content- knowledge tutors. However, no differences were found in tutee performance on revision. The findings are discussed in terms of the set-up of this study and implications for improving the effectiveness of peer tutoring

3D Spheroid Culture Systems for Metastatic Prostate Cancer Dormancy Studies and Anti-Cancer Therapeutics Development.

Prostate cancer is the most common non-skin cancer in United States men. Despite recent advances, mortality still remains high due to the emergence of therapy-resistant cancer cells that metastasize. Recently it has been postulated that only cancer stem cells (CSCs) are able to establish metastases, and therefore are the essential targets to destroy. Unfortunately, current use of CSCs is limited by the small number of CSCs that can be isolated, and the difficulty of culturing the CSCs in vitro. Furthermore, current in vitro-based metastatic prostate cancer models do not faithfully recreate the complex multi-cellular, three-dimensional (3D) tumor microenvironment seen in vivo. It is therefore crucial to develop effective in vitro prostate cancer culture and testing systems that mimic the actual in vivo tumor niche microenvironment. Here we utilized novel microscale technologies to develop an accurate 3D metastatic tumor model for detailed study of metastatic prostate cancer dormancy as well as accurate anti-cancer therapeutics screening and testing in vitro. Guided by the observation that prostate cancer cells parasitize and stay quiescent in the hematopoietic stem cell niche that is rich in osteoblasts and endothelial cells in vivo, a microfluidic device was established to create 3D spheroid culture of prostate cancer cells supported by osteoblasts and endothelial cells. This 3D metastatic prostate cancer model recapitulates the physiologic, dormant growth behavior of prostate cancer cells in the hematopoietic stem cell niche. Furthermore, we developed a hanging drop-based high-throughput platform for general formation, stable long-term culture, and robust drug testing and screening of 3D spheroids. Using this platform, we found significant differences in drug sensitivities against cells cultured under conventional 2D conditions versus physiological 3D models. A variety of techniques and methods were also established to specifically pattern the spatial localization of different co-culture cell types within a spheroid in this platform for accurate engineering of the 3D metastatic prostate cancer niche microenvironment. Collectively, these biological findings and technological innovations have led to advances in the understanding of prostate cancer biology and progress towards development of novel tools and therapeutics to fight against tumorigenic cancer cells.Ph.D.Biomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/86364/1/ahsiao_1.pd

Effects of using a peer support system to optimise knowledge sharing in learning networks: a cognitive load perspective

In a non-formal learning network, knowledge sharing is often desirable when working on complex tasks. However, without support, learners need to first find a tutor and then maintain social interaction, which, according to cognitive load theory, may hamper learning. After all, the extraneous load imposed by these two activities and the intrinsic load imposed by the task itself might easily overload learners' cognitive capacity. We compared the effects of using a peer support system with an automatic tutor assignment and an interaction tool (wiki) to a forum and control group (without any support) on learners' cognitive load and learning efficiency for simple and complex tasks. The results did not significantly show that this peer support system was instrumental in reducing cognitive load and improving learning efficiency. However, the study did shed an illuminating light on how to apply instructional guidelines of cognitive load theory to non-formal learning networks

Effect of using peer tutoring to support knowledge sharing in Learning Networks: A cognitive load perspective

Hsiao, Y. P., Brouns, F., & Sloep, P. B. (2010, 4 November). Effect of using peer tutoring to support knowledge sharing in Learning Networks: A cognitive load perspective. Presentation at ICO-Toogdag, Amstelveen, The Netherlands: VU Amsterdam.In Learning Networks, learners need to acquire knowledge through knowledge sharing with other participants. However, without support, learners have to self-organize knowledge sharing by finding a relevant knowledge sharer, structuring the interaction and maintaining the communication process. According to cognitive load theory, these activities could induce extraneous load because they are not directly relevant to learning itself but to the learning environment. When working on complex tasks, extraneous load becomes detrimental to learning effectiveness and efficiency because learners have to simultaneously deal with the high intrinsic load of the complex tasks and the extraneous load of knowledge sharing activities. For such tasks, it is considered imperative to reduce extraneous load and we used a peer tutoring system to support knowledge sharing by matching learners together, providing role specifications and an interactional tool of wiki. This study investigated the effect of using this peer tutoring system to support knowledge sharing on different levels of task complexity in the Learning Network of Internet Basics. Based upon cognitive load theory, an interaction effect was expected that peer tutoring would reduce extraneous load and result in better learning effectiveness and efficiency only on complex tasks. In addition, we expected that using peer tutoring would result in better knowledge sharing on complex tasks. However, these hypotheses were not confirmed because of the limited number of knowledge sharing inquiries: this indicated that the peer tutoring support was not used sufficiently to have effects on cognitive load, learning effectiveness and efficiency. The major contributions of this study were i) we explored the effect of using different supports of knowledge sharing on humans’ cognitive system in a non-formal Learning Network by applying cognitive load theory, ii) we showed the challenges of data collection, especially for measuring cognitive load in such learning environments

Effects of peer-tutor competences on learner cognitive load and learning performance during knowledge sharing

Hsiao, Y. P., Brouns, F., Van Bruggen, J., & Sloep, P. B. (2012, 19-21 October). Effects of peer-tutor competences on learner cognitive load and learning performance during knowledge sharing. Presentation at IADIS International Conference Cognition and Exploratory Learning in Digital Age (CELDA) 2012, Madrid, Spain.In Learning Networks, learners need to share knowledge with others to build knowledge. In particular, when working on complex tasks, they often need to acquire extra cognitive resources from others to process a high task load. However, without support high task load and organizing knowledge sharing themselves might easily overload learners’ limited cognitive capacities because learners first have to find relevant peer tutors (i.e., those who provide help) and then maintain the social interaction. We propose to design a peer-support system that selects tutors and provides support during knowledge sharing. The pilot study reported here investigated the effects of two peer tutor competences, tutoring skills vs. content knowledge, on tutees’ (i.e., those who need help) cognitive load and learning performance. The results show that tutees supported by tutors with tutoring skills experienced lower cognitive load and had better learning performance than did tutees supported by tutors with content knowledge. This is in line with our assumption, but for confirmation we need to gather more data in a full study. We need to first use a task that requires learners to rely on others to trigger higher cognitive skills to deal with high task load. Secondly we need to find a modus to ensure that the tutors follow the instructions to apply the particular competence