Hello, you could explore whether AI-driven platforms are effective in language learning. You can build teaching materials by using diffit.me or twee.com applications.

Alternatively, you can investigate whether exposing students to extracts of films in English (with subtitles) can increase their language proficiency.

You can prompt students to translate such subtitles in their first language.

At the end of the lessons, you should envisage quality questionnaire where you ask for the students' engagement in the lesson and the quality of the teaching materials.

You can conduct your lessons over a certain period of time, so that you can prepare a pre-lesson test on the students' level of English (as a foreign language) and, after some time, a post-lesson test of English, to verify if they improved their skills.

Good luck!

another idea: you can generate automatic subtitles on short English videos and ask students to correct them. Afterwards, you can expose students to the official subtitles in English and ask them to compare their corrections to the official subtitles.

To download videos from youtube with subtitles you can consider the software 4KVideo downloader. To generate automatic subtitles you can consider Clideo or Veed (although they do have very restrictive freemium plans now).

The best way to choose a dissertation topic is to think about what intrigued you most across all of your course work and then see what unanswered questions remain which you could reasonably address with research.

Do you face or see any problems or promising possibilities in implementing technology in language learning? If you find something to be discussed on the topic, then you may start with that. You may work with a new technological model or app which can be used as a tool of language learning.