Estimation of summary protective efficacy using a frailty mixture model for recurrent event time data.

Recurrent event time data are common in experimental and observational studies. The analytic strategy needs to consider three issues: within-subject event dependence, between-subject heterogeneity in event rates, and the possibility of a nonsusceptible fraction. Motivated by the need to estimate the summary protective efficacy from recurrent event time data as seen in many infectious disease clinical trials, we propose a two-part frailty mixture model that simultaneously accommodates all the three issues. In terms of vaccine action models, the proposed model is a combination of the 'all-or-none' and the 'leaky' models, and the summary protective efficacy is a unified measure of the vaccine's twofold effects in completely or partially protecting the vaccinated individuals against the study event. The model parameters of interest are estimated using the expectation-maximization algorithm with their respective variances estimated using Louis's formula for the expectation-maximization algorithm. The summary protective efficacy is estimated by a composite estimand with its variance estimated using the delta method. The performance of the proposed estimation approach is investigated by a simulation study. Data from a trial of malaria prophylaxis conducted in Ghana are reanalyzed

Examining facilitators' habits of mind in an asynchronous online discussion environment: A two cases study

Asynchronous online discussion has been widely used by faculty members and students in schools and universities. Previous research has examined how factors such as the discussion activity, knowledge about the discussion topic, and the behaviour of other participants can affect learner participation. This study explored student facilitators' influence in promoting learners' participation in terms of their exhibited habits of mind. The following habits of mind of the facilitators were examined: (a) awareness of own thinking, (b) accurate and seeks accuracy, (c) open minded, (d) taking a position when the situation warrants it, and (e) sensitive to other. A two-cases study methodology approach was used in this study. The habits of "awareness of own thinking" and "open minded" were found to be exhibited more often by the student facilitators in the two cases. When we zoomed into the top 30% of the forums in terms of learners' participation, we also found that the frequency of habits of mind, "awareness of own thinking" and "open minded", were exhibited more often by the facilitators.published_or_final_versio

Asynchronous online discussion: Instructor facilitation vs. peer facilitation

Asynchronous online discussion forums have been widely used in schools and universities. They form an integral part of e-learning and blended learning. Many researchers and educators use asynchronous online discussion activity to develop student thinking skills, problem solving skills, and others. There are many factors that may affect student participation in asynchronous online discussion forums such as discussion topics, group size, ground rules of the discussion forums, facilitation skills, and others. We believe that facilitators play an important role in the success of asynchronous online discussion. Usually instructors or students serve as facilitators for online discussion activities. In this study, we explore participants" preference in terms of facilitator (instructor facilitator vs. peer facilitator). In addition, we also found out the reasons for their preference. © 2010 Wing Sum Cheung & Khe Foon Hew.published_or_final_versio

Using asynchronous online discussion in education: lessons learned over the last ten years

Over the last ten years we have been exploring the educational use of asynchronous online discussion (AOD) at a university in Singapore. While the advantages of using AOD have been widely reported, the challenges or problems of using it have received lesser attention. This paper briefly reports the three main challenges we faced in actual lesson implementations of AOD in the last ten years. These challenges are “Assignment mode”, “No time for discussion”, and “lack of in-depth critical thinking”. In addition, we also made some suggestions to overcome them.postprin

A review of research methodologies used in studies on mobile handheld devices in K-12 and higher education settings

Mobile handheld devices are increasingly being used in education. In this paper, we undertook a review of empirical based articles to summarise the current research regarding the use of mobile handheld devices (personal digital assistants/PDAs, palmtops, and mobile phones) in K-12 and higher education settings. This review was guided by the following four questions: (a) How are mobile handheld devices such as PDAs, palmtops, and mobile phones used by students and teachers? (b) What types of research methods have been applied using such devices? (c) What data collection methods are used in the research? and (d) What research topics have been conducted on these handheld devices in education settings, as well as their related findings? We summarise and discuss some major findings from the research, as well as several limitations of previous empirical studies. We conclude by providing some recommendations for future research related to mobile handheld devices in education settings.published_or_final_versio

Design and evaluation of two blended learning approaches: Lessons learned

In this paper, we share two blended learning approaches used at the National Institute of Education in Singapore. We have been using these two approaches in the last twelve years in many courses ranging from the diploma to graduate programs. For the first blended learning approach, we integrated one asynchronous communication tool with face to face tutorials, classroom discussions, and a reflection session. For the second blended learning approach, we integrated two asynchronous tools with face to face tutorials in a course. We discuss the theoretical foundation of the two blended learning approaches. In addition, we share insights from these two blended learning approaches, based on the students' data (online postings, questionnaires, reflection logs, and interviews), as well as our own reflections. Finally, we describe and discuss several important lessons learned that could inform the design of future instructional strategies in implementing blended learning in university teaching and learning settings.published_or_final_versio

The relationship between group size and advanced level knowledge construction in asynchronous online discussion environments

This study is part of a funded research project that examines possible factors that may influence students' advanced level of knowledge construction. This study examines if group size of the online discussion is related to the frequency of advanced level of knowledge construction occurrences. Group size of an online discussion refers to the number of people who contributed in the discussion. Advanced levels of knowledge construction refer to levels II, III, IV, or V of Gunawardena, Lowe, and Anderson's (1997) interaction analysis model. Data were collected from 28 asynchronous online discussion forums. Results showed a significant positive correlation between group size and advanced level knowledge construction; suggesting that the larger the group size of the online discussion is, the more frequent the occurrences of advanced level knowledge construction would be. Further analysis between the more successful and less successful forums suggested that a certain critical mass, which appears to be a group size of about 10 participants may be required to direct the discussion to advanced levels of knowledge construction. © 2010 Khe Foon Hew & Wing Sum Cheung.published_or_final_versio

Exploring the use of asynchronous online discussion and vicarious learning in Citizenship Education: a case study of a Singapore School

This paper is part of a larger study investigating how teachers can foster positive student attitude toward their country. Specifically, in this paper presentation, we described the use of vicarious experience along with asynchronous online discussion forums at a Singapore primary school in an attempt to teach one major citizenship education messages – Singapore is our homeland; this is where we belong. In an asynchronous online discussion environment, students have more time to make explicit their preexisting personal beliefs about Singapore, and reflect on them – one of the key prerequisites of promoting belief change. Vicarious experience is learning through the experience of others. In our case, it was students learning through the experience of other people such as teachers, and their peers of what Singapore meant to them by means of written narratives, pictures or video clips. We provide some preliminary findings about what students felt about this learning approach, as well as the challenges in conducting it.postprin

Critical thinking in asynchronous online discussions: examining the role of the student facilitator

This paper is part of a larger study that investigates the types of facilitation techniques exhibited by student facilitators and how these techniques may foster in-depth levels of critical thinking in asynchronous online discussions. Data were collected from ten discussion forums, involving education major students. The top 30% of forums in terms of the most number of in-depth critical thinking incidences were first identified (i.e., higher-level group). Next, the bottom 30% forums were identified as the lower-level critical thinking group. Results indicated that student facilitators in the higher-level group acknowledged the participants’ contributions, and posted more questions than their counterparts in the lower-level forums. Facilitators in the high-level group also tended to pose questions throughout the entire discussion, unlike those in the lower-level group who only posted questions at the start of the discussion. Six types of questioning techniques were found. Directions for future research are proposed.postprin

Scaffolding interaction in asynchronous online discussion through peer facilitation

This study aims to identify the peer facilitation techniques that could scaffold interaction in asynchronous online discussion forums. The findings of this study suggest that scaffolding interaction in asynchronous online discussion through peer facilitation could be achieved through the use of the following five peer facilitation techniques: "showing appreciation", "considering others' viewpoints", "general invitation to contribute", "questioning" and "challenging others' points".published_or_final_versio