I believe since Educational Technology is an eclectic field, research should be carried out in all aspect of the field and NOT stream lined to just a particular aspect.

The profound study of didactics is imo the key Damola Olugbade

You can add also the history of educational technology.

https://opentextbc.ca/teachinginadigitalage/chapter/section-8-1-a-short-history-of-educational-technology/

https://www.k12academics.com/educational-technology/history

https://www.sutori.com/en/story/history-of-educational-technology--AvgE5epPRUebhcNA51Uw5FzF

https://edutechwiki.unige.ch/en/Educational_technology#:~:text=Educational%20technology%20in%20way%20could,teaching%20machines%20in%20the%201920%27.

https://en.wikipedia.org/wiki/Great_Didactic

Chapter Open Learning Environments

For early researchers in Educational Technology, selecting the right research focus is crucial as it can shape their academic and professional trajectory.

A possible approach for early researchers in educational technology is to adopt a design-based research (DBR) perspective.

Design-Based Research is a methodology that involves iterative cycles of designing, implementing, and evaluating innovative interventions in authentic settings, with the aim of addressing complex educational problems and generating theory and evidence. It helps researchers to engage in collaborative and interdisciplinary work with practitioners, learners, and other stakeholders, and to produce both practical and theoretical outcomes that can inform and improve educational technology. DBR also offers opportunities for creativity, experimentation, and reflection, which are valuable skills for early researchers in any field.