Pruebas de las Técnicas de pre procesamiento de imágenes

The debate about quantitative and qualitative research at an epistemological level stemmed from a perception that each was distinct and related to competing paradigms (Bryman, 2006, p. 113). This view was promoted in Kuhn’s influential publication ‘The structure of scientific revolutions’ (1970) where qualitative and quantitative approaches to research could not be combined due to incommensurable issues. Two important issues that still persist are the paradigm-method fit and the best paradigm and have inspired considerable debate regarding the philosophical basis of mixed methods research. The paradigm-method fit issue relates to whether or not philosophical paradigms (e.g., post positivism, constructivism) and research methods fit together whereas the best paradigm issue relates to what philosophical paradigm is the best foundation for mixed methods research (Hanson et al., 2005, p. 225).

post positivist philosophical assumptions and naturalistic assumptions in terms of epistemology (how we know what we know), ontology (the nature of reality), axiology (the place of values in research), and methodology (the process of research). This led to a separation between traditional inquiry paradigms and naturalistic paradigms

where some researchers have argued, for example, that a post positivist philosophical paradigm, or worldview, could be combined only with quantitative methods and that a naturalistic worldview could be combined only with qualitative methods (Reichardt & Rallis, 1994). From this perspective, mixed methods research was viewed as untenable or incommensurable because certain paradigms and methods could not fit together legitimately (Smith, 1983). Reichardt and Cook (1979) suggested a different approach where different philosophical paradigms and methods were compatible. Greene and Caracelli (2003) supports this position and argue that multiple methods may be used in a single research study to, take advantage of the representativeness and generalizability of quantitative findings and the in depth, contextual nature of qualitative findings.

Tashakkori and Teddlie (2003) suggest that pragmatism is the best paradigm for mixed methods research. Pragmatism is a set of ideas that draws its inspiration from “what works”, and leads to the use of diverse approaches and valuing both objective and subjective knowledge (Cherryholmes, 1992). Rossman and Wilson (1985) strongly associate pragmatism with mixed methods research. They differentiated between methodological purists, situationalists, and pragmatists. The purists believed that quantitative and qualitative methods derived from different, mutually exclusive, epistemological and ontological assumptions about research. The situationalists believed that both methods have value but that certain methods are more appropriate under certain circumstances. The pragmatists, in contrast, believed that, regardless of circumstances, both methods might be used in a single study. For many mixed methods

researchers, then, pragmatism has become the answer to the question of what is the best paradigm for mixed methods research. Tashakkori and Teddlie (2003, p. 20) have attempted to formally link pragmatism and mixed methods research, arguing that, the research question should be of primary importance and more important than either the method or the theoretical lens, or paradigm that underlies the method. This position is supported by Bryman (2006, p. 118) where the primacy of the research question is instrumental in bringing together qualitative and quantitative research.

There are a number of different perspectives in the natural hazards and risk literature. On one end of the risk research spectrum is a strong technical or realist approach to risk. In this perspective, the environment is considered to be external to society and capable of being measured objectively. Uncertainties that have no predictable probability are excluded from technical risk analysis, as are social constructions or perceptions (Lupton 1999). At the other end of the spectrum are constructionist (or relativist) approaches that emphasize the ways in which people assign meaning to their world (Irwin 2001) Strong constructivist perspectives approach risk as something only subjectively known. What people think and the cultural

worldviews of people are what make risks real (Raynor 1992).

The ontological position of a disaster researcher will undoubtedly lead to the way in which knowledge about disasters is constructed and understood and therefore will determine the overall epistemological position. Disaster studies reflect research positions of both positivist and interpretist nature. The positivist taking a natural science approach where knowledge about disasters is generated based on generalisable

propositions where as the interpretivist will generate knowledge that is based on the subjective meaning of social action and is not necessarily generalisable (Bryman and Bell, 2007). However it may be necessary to rise above the epistemological differences between objectivist/positivist and constructivist /interpretivist paradigms and rely as

much upon qualitative as quantitative methods in order to both conceptualise and estimate the risk from natural or man made disasters. Action and decision inherent in defining disaster risk require the creation of interactions between subjective risk perception and the scientific need for objective measurement (Cardona, 2003). Kreps (1989) appeared to have the foresight of the way forward espoused by Cardona where he comments “I am certain that a cooperative dialogue based on mutual respect for competing epistemologies is the path to scientific progress in disaster research” (p. 280).

Having described the epistemological conflicts in the field of disaster

management, a discussion on the methods used within the domain will equally reflect the diversity described previously. The methods of disaster research are not

distinguishable from those used throughout mainstream social sciences. Yet these methods must be applied under sometimes exceptional circumstances created by a social situation characterised by non-routine, life threatening physical destruction (Stalling, 2005a). Researchers in this discipline need to understand how the disaster context affects the application of the methods of research. Standard methods of research in the field of disaster studies are for example, qualitative field studies or quantitative survey research (Stalling, 2005b).

The review of literature on disasters and emergencies revealed that qualitative, quantitative and mixed methods approaches were all being utilised to generate

knowledge about the domain. Elder et al. (2007) uses six focus groups within a qualitative methodology to elicit information on evacuation decisions in the Katrina disaster whilst in quantitative studies that took place in the United States and New Zealand, Kang et al. (2007) and McIvor and Paton (2007) use survey methods to generate information on disaster behaviour. A mixed methods approach was used to examine adaptive behaviour in the Katrina disaster. This study used a 54 item survey for

the quantitative data collection and field observations and interviews were used in the qualitative element (Adeola, 2009). Having reviewed the generally position of

epistemological and paradigmic issues regarding mixed methods, focus then turned to the domain of disaster and emergency management and how epistemological and paradigmic issues affect research in this area. The next section will explore mixed methods as both a methodology and method of approach.