Theory is needed to provide a general interpretation framework, as explained by John Creswell:

[Theory] is used as a broad explanation for behavior and attitudes, and it may be complete with variables, constructs, and hypotheses. Researchers increasingly use a theoretical lens or perspective in qualita­tive research, and advocacy perspective that shapes the types of questions asked, informs how data are collected and analyzed, and provides a call for action or change (Creswell, J. H. Research design. Qualitative, Quantitative and Mixed Methods Approaches. Los Angeles etc.: Sage, 2009).

The theoretical framework is constructed by locating, reviewing, expanding and selecting the information, which must be systematized in the form of summaries and fact sheets, either by topics or by authors. Since this is a fundamental aspect of all research, and it is a novel procedure, it is a very useful practice in which they begin to build the theoretical framework, looking for research centers and publications relevant to their object of study. information gathering consists of searching for information on the subject in scientific journals, professional journals, non-specialized journals and publications, summaries of researchers' associations, databases and newspaper archives. Once the collection is complete, the materials are evaluated and the ideas (topics, subtopics, authors, etc.) are organized.

We recommend three possible approaches of this type: grounded theory, Action-Network Research and mixed methods.

The first, following Creswell, op. cit. consists of a series of methods "suitable for studying individual processes, interpersonal relations and the reciprocal effects between individuals and larger social processes". Its objective is to generate inductive theories applied to a specific object of study, it is based on the systematic collection of data, while at the same time analyzing them through an iterative design and the collection of samples until reaching a moment of theoretical saturation, when they are no longer productive, which are analyzed on the basis of previously defined categories of analysis that are adjusted during the research process until the central ones are discerned.

Action-Network Research "leads to better research because the practical and theoretical outcomes of the research process are grounded in the perspective and interests of those immediately concerned, and not filtered through an outside researcher's preconceptions and interests" (Reason and Bradbury, 2001: 4). It is collaborative, it is based on considering the interests of the community being studied, therefore the participants help in the design of the research itself to produce practical knowledge. In a way, it is said to democratize the research process, and places the emphasis on decision making.

Finally, a mixed methods approach employs quantitative and qualitative methods to address the different objectives, questions and hypotheses posed in the research, and is especially useful for answering complex research questions and problems.