This with effectiveness of teaching or learning versus media and communication technology use is a tricky area. Furthermore, teaching and learning are not the same process.
You can examine if students and/ or teachers thought it was fun or interesting to teach or study a course in a specific way enabled by digital tools, but you can hardly conclude much about effectiveness from that. What should you compare with? The next class? The same students studying another course? One group studying ”without” ICTs and one with? But there is no one studying in any kind of schooling ”without” digital or analogue ICTs anyway. in all these scenarios, the influential factors are too many to possibly keep track of.
What can be examined, however, is how new ICTs can create better access to education, for more kinds of students. With ”adaptive learning” courses, built on learning analytics modifying the course for the individual, there we can possibly talk about effectiveness in the sense that a student does not have to waste time on what he or she already knows, on assignments too easy - or too difficult. Adaptive learning models use the more genuine function of digital ICTs to process information, not only, as ICTs in education mostly does today, to decrease the friction of information (which is the latest on a very old human project, beginning probably with writing.
I suggest you embark on systematic literature of literature on digital transformation. Do a thematic analysis of it and map out the several factors that have an impact on learning using technology. Find experts in your context of research to measure the relevance of these factors to your study domain. their recommendation can suggest the variables you are looking for.
I think that measuring the effectiveness of the digital transformation of learning needs paragraphs that distance the student from bias and express the behavior accurately