坦桑尼亚信息通信技术（ICT）等教育技术的整合仍处于起步阶段。因此，该国高等教育教学模式仍以传统的面授为主。此外，在坦桑尼亚高等教育领域中，提高技术整合和建设现代教学环境的策略（包括在线学习）尚未得到充分探索。通过相关研究，我们可以提升该国高等教育中整合技术工具的知识和技能，从而有可能促进其教育方式转型，并提高其参与全球经济竞争的能力。

本研究旨在改进混合学习环境中在线学习的设计，以加强和支持坦桑尼亚高等教育的协作学习实践。为此，笔者提出了核心研究问题：在坦桑尼亚高等教育中，学生如何在混合学习环境中参与在线协作学习？为了探究这一问题，笔者使用基于设计的方法（design-based approach，以下简称DBR）和社会建构主义视角设计在线协作学习干预，并在University of Dar es Salaam的混合学习环境中实施。具体而言，本研究试图探究和理解本科生在在线平台（Slack）上学习教育媒体和技术课程时产生的互动行为。研究数据来源于教育技术模块的2名教师和28名本科二年级学生，通过线上和线下的方式（具体包括访谈、在线观察、线上小组座谈和反思日记）进行收集，并采用专题分析进行数据分析。本研究主要有三个研究问题：第一个研究问题旨在探索实施在线协作学习干预前University of Dar esSalaam的教学性质。研究结果表明，在实施在线协作学习干预之前，促进生生之间以及师生之间互动的教学环境有限。此外，虽然教师有参与在线教学的经验，但大多数学生之前没有参与在线学习的经验。  

第三个研究问题是在实施在线协作学习干预后提出的，即要求参与者分享他们的教学与学习经验。研究结果表明，大多数参与者在设计他们参与的在线协作学习干预中有积极的经验。参与者还解释了他们在开展在线协作活动时遇到的问题，这些问题主要与组织与实施小组讨论以及技术有关。他们依据经验建议改进在线协作学习干预的设计，包括增强设计的趣味性和吸引力，改进在线环境中的学生评价，以及对在线互动进行额外的指导和支持。

总之，本研究在实践和理论上都有创新之处。除了设计在线学习环境外，研究还设计了在线协作学习活动，并揭示了在坦桑尼亚高等教育环境中实施该活动的第一手经验。本研究还对坦桑尼亚学生（其中大多数缺少在线环境学习的经验）在设计的在线学习环境中如何进行互动和参与有了新的认识和见解。教育技术的整合能够促进学生有效学习、实现社会公平以及应对全球新冠疫情危机。本研究通过批判性研究方法进行探究，对教育技术、比较教育和高等教育领域都有着重要的借鉴意义。

In Tanzania, integration of technology in education such as Information and Communication Technology (ICT) is still in its infant stage. Consequently, teaching and learning in higher education is dominated by conventional face-to-face methods. However, strategies of improving integration of technology and construction of modern teaching and learning environments including online learning in Tanzanian higher education have not yet been adequately explored. Generation of such understanding could activate knowledge and skills of integrating technological tools in Tanzanian higher education which has potentials of transforming education and enable the country to strive and compete in the global economy.

In this doctoral dissertation, I aimed to improve the designing of online learning in blended learning environments to enhance and support collaborative learning practices in higher education in Tanzania. To achieve this goal, I asked the central research question: How do students engage in online collaborative learning in blended learning environments in higher education in Tanzania? To explore this question, I used the design-based research (DBR) and social constructivism lenses to design online collaborative learning intervention and implement it in a blended learning environment at the University of Dar es Salaam. Specifically, I sought to explore and understand interactions of undergraduate students when studying an educational media and technology course in a designed online platform (Slack). In implementing this study, data were collected from two instructors of an educational technology module and 28 undergraduate students who were in the second year and they were enrolled in this module. Data were collected by using online and offline sources, namely interviews, online observation, online focus groups and reflective diary. The data was analysed by using thematic analysis technique.

The research was guided by three research questions. The first research question seeks to explore the features of teaching and learning before implementation of online collaborative learning intervention at the University of Dar es Salaam. Findings of the study revealed that before implementation of online collaborative learning intervention, there were limited teaching and learning environments that facilitate interactions among students and between students and instructors. Also, while instructors had experiences of participating in online teaching and learning environments, the majority of students had no previous experience of participating in online learning environments.

The second research question was asked during implementation of online collaborative learning intervention. It explored the nature of students’ interactions when they engage in two collaborative activities in a designed online environment. Different dimensions of social interactions were observed when students were doing two collaborative activities. However, in both activities, the interactions of students were dominated by contribution statements. It was also observed that the use of the eLearning platform was improved in the second collaborative task whereby different channels of designed eLearning were used as intended when doing the second collaborative task than it was in the first collaborative task.

The third research question was asked after implementation of online collaborative learning intervention and it asked participants to share their experiences of teaching and learning in it. Findings indicate that the majority of participants had positive experiences in designing online collaborative learning intervention that they participated in. Participants also explained the tensions and contradictions that they experienced in doing online collaborative activities which were mainly related to the organization and implementation of group discussions as well as technological issues. Based on their experiences they suggested improving the design of online collaborative learning intervention by considering making learning more fun and engaging, improve evaluation of students in an online environment and provide extra directions and support in online interactions.

Ultimately, this research project has made both practical and theoretical original contributions. On top of designing an e-learning environment, the project designed online collaborative learning activities and revealed first hand experiences of implementing it in Tanzanian higher education context. Additionally, the project generated new understanding and insights into how Tanzanian students, of whom majority of them had no experience of studying in online environments, interacts and engages in a designed online learning environment. The study has valuable implications to the field of educational technology, comparative education and higher education by critically studying integration of technology in education which has proven to facilitate effective learning, social justice and tackling learning crisis such as COVID-19 pandemic at national and global level.