Definitions

The definition of: 
1. Cross Disciplinary 

Cross-disciplinary refers to knowledge that explains aspects of one discipline in terms of another. Common examples of cross-disciplinary approaches are studies of the physics of musics or the politics of literature. 
(http://en.wikipedia.org/wiki/Disciplinary#Cross-disciplinary)

2. Trans Disciplinary 

Trans Disciplinary involves the combining of two or more academic disciplines into one activity (e.g. a research project). It is about creating something new by crossing boundaries, and thinking across them
(http://en.wikipedia.org/wiki/Transdisciplinary)
Describing a study which runs across traditional subject boundaries such as arts and science.
(http://www.answers.com/topic/transdisciplinary#ixzz2AtIEY5OK)

3. Qualitative Research

Qualitative research is a method of inquiry employed in many different academic disciplines, traditionally in the social sciences, but also in market research and further contexts. Qualitative researchers aim to gather an in-depth understanding of human behavior and the reasons that govern such behavior. The qualitative method investigates the why and how of decision making, not just what, where, when. Hence, smaller but focused samples are more often needed than large samples.
(http://en.wikipedia.org/wiki/Qualitative_research)

4. Ethnographic Studies

Methods of qualitative research developed by anthropologists, in which the researcher attends to and interprets communication while participating in the research context. 
(http://medical-dictionary.thefreedictionary.com/ethnographic+studies)