Grounded theory and phenomenology studies are common approaches to qualitative research, and they are mostly used by nurses

Grounded theory and phenomenology studies are common approaches to qualitative research, and they are mostly used by nurses. Although the two research approaches have differences, they have so much in common.
Differences
Phenomenology, first described by Edmund Husserl and Martin Heidegger began from philosophy, and its main goal is to describe and explore experiences, which are only made possible by data collection from people who have stayed or lived through those particular experiences (Todres & Holloway, 2010). Data is limited to interviews, and the findings are only reported as rich descriptions of the experience drawn on features that have been identified during the analysis of the data. On the other hand, Grounded Theory emerged from sociology and was first influenced by Barney Glaser and Anselm Strauss as a qualitative methodology. Their main objective was to develop a grounded theory to explain the phenomenon that was being studied. Grounded theorists aim at including all the sources of data that might contribute to theory development, unlike the phenomenologists.
Similarities
Both research methods focus on real life situations, and although they do not fit all the studies, they require a high level of interaction between the situation, groups or individuals and the researcher (Todres & Holloway, 2010). Both phenomenologists and grounded theorists seek to collect and analyze data from the perspective of the participants, and they ensure that their research results are not affected by ideas which are preconceived. Sometimes it is tough to differentiate between the grounded theory approach and phenomenology especially for those using qualitative research. However, considering the theoretical and philosophical bases can bring out the distinction between the two methodologies and their effect on how research is conducted.
 
Reference
Todres, L., & Holloway, I. (2010). Phenomenological research. In: Gerrish K, Lacey A (eds) The Research Process in Nursing. Oxford, Blackwell Publishing Ltd.