You can use different types of open data in your studies. This open data can be interviews, questionnaires, statistics, or measurements or language corpuses. You can use different types of open data as part or your thesis or research. Open data can be found through various search portals.
Read about statistics at Statistics Finland website:
SAGE Research Methods database contains tools and other materials regarding methods and how to conduct research (such as writing a literature review). Try the interactive Methods map or use the Project planner to map out your project.