This special issue in Education and Adolescent Students’ Well-being is a constellation of five papers highlighting various issues in the education field, and issues of concern to adolescent students’ development and well-being. In particular, the issue has two papers on online violence and sexual exploitation among adolescent students in secondary schools. There are also two papers in teacher education focusing on the use of technology in science and mathematics teaching, as well as a comparative analysis on teacher professional development—the case of China and Tanzania. Assessment and feedback have also been delineated in one of the five papers. The papers were first reviewed by the guest editor and later sent to peer reviewers who provided scholarly comments and recommendations for the suitability of the paper for publication consideration in a special issue. The final review and comments were provided by the guest and chief editors, and authors responded to most of the comments from the reviewers and the editors. However, the authors remain liable for the content of their papers. Rapid advancements in information and communication technology in terms of the internet, social media, and cellphones have come with both benefits and disadvantages. The paper by Dr Hezron Z. Onditi and Prof. Jennifer Shapka examines the prevalence of cyberbullying and cybervictimization, and the associated predictors among Tanzanian secondary school adolescents. The authors find that cyberbullying is an emerging problem of concern among Tanzanian secondary school adolescents who have access to the internet and cellphones. They further show that more time spent online, use of devices in a private location, and sharing devices are associated with increased risks in engaging in cyberbullying others and for being victimized online. They conclude that technology is ubiquitous, thus, the effects transcends physical geographical boarders; calling for holistic education and awareness programmes on responsive use of the internet and cellphones among children and adolescents. The use of technology in teaching and learning has currently gained popularity among educators and researchers. The paper by Dr Ayoub Cherd Kafyulilo and Dr Frank Tilya examines the effectiveness of learning technology by design in the development of inservice science teachers’ competencies of integrating technology in science and mathematics teaching in Tanzania. In a pre- and post-intervention assessment of teachers’ technological and pedagogical content knowledge (TPACK), the authors find a significant improvement of teachers’ technology integration competencies among teachers who participated in technology-integrated design lessons in design teams. This study further shows that students also reported a high level of satisfaction and mastery of lessons and difficult concepts in science and mathematics that were taught using technology. The authors conclude that teachers’ collaboration to design technology-integrated lessons is an important and effective approach worth adapting in teachers’ professional development. Assessment and evaluation are important components in teaching and learning. Dr Florence Kyaruzi researched students’ mathematics self-efficacy and use of teachers’ feedback in improving mathematics performance in secondary schools in Tanzania. Using structural equation modelling and focus group discussions, the author finds that despite poor mathematics performance trends in Tanzania, students report high levels of mathematics self-efficacy and perceptions about the use of teachers’ feedback. The author further reveals that students’ self-efficacy and use of teacher feedback jointly predicted their mathematics performance to some extent. Finally, the paper recommends intervention and education programmes focusing on improving students’ mathematics self-efficacy and in using teachers’ feedback. The paper by Dr Mjege Kinyota, Dr Patrick Kavenuke and Dr Rehema J. Mwakabenga is a comparative study that explores professional development of teachers in Tanzania by drawing lessons from Chinese school-based professional learning communities (SBPLCs). They indicate that Chinese schools have made significant achievements in SBPLCs by supporting teachers’ collaborative learning and research in rural and urban areas. The authors relate the Chinese success with a strong government support and commitments on the part of teachers and school leaders. They conclude by pointing out six key major lessons that Tanzania can learn from China: formalizing professional learning at school level; developing an explicit teacher professional development policy; allocating specific time for teachers’ professional learning in schools; offering financial support to schools for teacher professional learning; encouraging individual teacher initiatives to engage in professional learning; and enhancing available professional learning activities. Child sexual abuse and its associated negative consequences has been an issue of global agenda. The paper by Dr Budeba Petro Mlyakado explores sexual exploitation among adolescent students in Tanzania. The author reveals that adolescents appear to engage in transactional sex, an exploitative sexual relationship, including sodomy due to economic hardships, lust for fashionable materials, and vulnerability. This study further associates sexual exploitation among adolescent students with various negative outcomes, including poor academic performance, school dropout, sexually transmitted infections (STIs), unintended pregnancies, and illegal abortions. Mlyakado concludes by pointing out challenges of giving services to adolescent victims of sexual exploitations including socio-cultural norms, lack of cooperation between service providers, secrecy, and the legal framework. This special issue has been published with support from the Dar es Salaam University College of Education. The Editorial Board is thankful to the DUCE management for this great support. Again, we would like to thank all authors who contributed to this issue but their papers could not meet the expectations of reviewers and the Editorial Board for publication in the JEHS. Mega congratulations to the authors of the five papers who made this special issue a reality. Thank you, our esteemed readers, and all those who consider the JEHS as an outlet for their scholarly work.