"Similar to analysis of primary qualitative datasets, thematic synthesis involves the systematic coding of data and generating of descriptive and analytical themes" (Nicholson et al, 2016).
Barnett-Page, E., & Thomas, J. (2009). Methods for the synthesis of qualitative research: a critical review. BMC medical research methodology, 9(1), 1-11. Full Text
Thomas, J., & Harden, A. (2008). Methods for the thematic synthesis of qualitative research in systematic reviews. BMC medical research methodology, 8(1), 1-10. Full Text
Caskurlu, S., Richardson, J. C., Maeda, Y., & Kozan, K. (2021). The qualitative evidence behind the factors impacting online learning experiences as informed by the community of inquiry framework: A thematic synthesis. Computers & Education, 165, 104111. Full Text
References
Nicholson, E., Murphy, T., Larkin, P., Normand, C., & Guerin, S. (2016). Protocol for a thematic synthesis to identify key themes and messages from a palliative care research network. BMC research notes, 9(1), 1-5. Full Text