Qualitative research designs aim to develop insight about subjective reality. They do not generally identify variables in advance; instead, the research itself is the process by which the important variables are identified. Qualitative studies rely primarily on observational and self-report forms of measurement. Specifically, ethnographic designs rely heavily on participant observation, while narrative designs rely heavily on narrative or semi-structured interviews. Results are typically in narrative format, and they are often published in books rather than journal articles. Qualitative research contributes to theory development in HDFS, and is important for its ability to contextualize development and relationships.