This thesis delves into the multifaceted aspects of media and technology adoption by teachers in schools from Chile and England, exploring their lives, concerns, conditions and characteristics that shape the use, adoption, or rejection of media, platforms, and software. I draw on a ‘deep mediatization’ approach in education to make visible processes by which media (traditional and digital) increasingly permeate various aspects of society, shaping the way people interact and experience the world. However, I argue that the mediatization approach tends to undertheorize causality claims, which can be attributed to a lack of reflection on the ontological underpinnings that sustain such claims. The described ontology neglects the shaping force of reflexivity and people's own concerns as a mediatory element between agency and structure in the relationship between technology and people and institutions.

Considering those shortcomings, I adopt critical realism as a complementary metatheory to develop a combined approach in which mediatization can dialogue with critical realist ontology, giving cultural contextual elements and agential power more weight and influence. Likewise, I also consider that critical realism, in its development of reflexivity, has not engaged productively with issues around media and communication, especially in terms of how media contents, infrastructure, and interactive elements participate in the elaboration and stimulus of concerns and internal dialogues.

To do this work, teachers' concerns and voices were placed at the centre of the analysis using an approach from within. First as a normative issue, considering that teachers are the core of the educational process and deserve to be heard and included in the analysis of their field. Second in practical terms I follow the idea that concerns are not only a subjective element with no sociological effects. Instead, concerns might also have a direct impact on the material world shaping practices, decisions, inclinations, and tendencies.

I also argue that in this comparative study, the accelerated adoption of new platforms and digital tools in learning environments, because of Covid-19, shows that the material circumstances, cultural background, historical context, and teachers' visions and concerns are conditions that enable or impede the uses of those new tools, enabling a causal analysis with an explanatory focus. In those terms and following critical realist ontology, I claim that agential powers influenced by (and influencing) culture matter more in some contexts than in others, which is exemplified by the pandemic scenario.

I conclude that there is a current process of mediatization in which structural forces, related to the surge of the EdTech market, are pushing for the adoption of certain technologies; however, that process is highly dependent on reflexivity and cultural and historical context, which conditions causal mechanisms and their effects.