Differences Between Qualitative Research and Quantitative Research and Their Integration in Social Science
( Mao Kuangyi 1904876)


Quantitative social research was originally inspired by the spectacular process of the natural sciences in the nineteenth century and therefore early social researchers set out to adopt what was called the ‘scientific method’ in their investigations. This method had been evolving in western thinking since about the mid-sixteenth century (the period of the Enlightenment) through the work of philosophers and scholars such as Copernicus, Bacon, Galilei, Kepler, Newton, Descartes, Hume, Comte, and Peirce. (Garratt and Li 2005; Jordan 2004) It postulates three key stages in the research process: (a) observing a phenomenon or identifying a problem; (b) generating an initial hypothesis; and (c) testing the hypothesis by collecting and analyzing empirical data using standardized procedures. ( Zoltan Dornyei 2007)
Research that can be considered ‘qualitative’ in retrospect has been around for about a century in the social sciences. The first text that tried to define ‘qualitative methodology’ – Glaster and Strauss’s (1967) The Discovery of Grounded Theory: Strategies for Qualitative Research – did not appear until the late sixties. The core features of qualitative inquiry are: emergent research design, working with a wide range of data including recorded interviews, various types of texts and images which capture rich and complex details, taking place in the natural setting, without any attempts to manipulate the situation under study, striving to view social phenomena from the perspectives of the ‘insider’, small sample size and interpretive analysis. (Zoltan Dornyei 2007)
The essential differences between qualitative research and quantitative research are mainly reflected in the different questions they answer, the different research procedures, the different research strategies, and the different research tools. The combination of the two cannot occur at the level of abstract epistemological and theoretical perspective, but only at the level of methodology, especially concrete methods. Using qualitative research methods and techniques at some stage in quantitative research, or using quantitative research approaches or methods as auxiliary to help in the study of qualitative studies, or studying the different aspects of a research by using qualitative and quantitative researches respectively, these are the common forms of the combination of the two research methods.
 
Differences between qualitative research and quantitative research
Since qualitative research and quantitative research are two research paradigms or research types with different properties, the works of various social researchers often compare these two research methods. The main differences can be categorized as the following from the perspectives of ontology, epistemology and methodology.
 
1. Different answers to questions
 All researches begin with the proposition of research questions. The task of research methods is to help researchers collect and analyze data correctly so as to answer research questions. As for qualitative research and quantitative research, one of the biggest differences between them is reflected in the different questions they answer. Generally speaking, quantitative research mainly focuses on and answers the questions related to the overall, relatively macro, relatively universal and focusing on objective facts, especially the questions about the relationship between variables. However, the main focus and answer of qualitative research is usually individual, relatively micro, relatively special, focusing on the subjective meaning, especially the interaction problem in specific situations. For example, social survey methods (one of the main methods used in quantitative studies) often only answer questions such as ‘how often mental illness occurs in a given population’ and ‘how often it varies among different social classes’. However, for some specific research questions, such as ‘what does living with a mental illness mean to the patient and his or her family’ and ‘what is the subjective meaning of the disease to the patient and his or her family’, the qualitative research method must be adopted to answer. That is to say, only qualitative research methods such as participant observation, in-depth interview, ethnographic research and case study can better help us answer the latter kind of questions.
 
The differences in how the researchers answered the questions reflected, in part, differences in the goals of the two types of research. Generally speaking, the objective of quantitative research is to describe the overall distribution, structure, trend and related characteristics, reveal the relationship between variables, and verify existing theoretical hypotheses. Qualitative research, on the other hand, mainly aims at revealing the process of phenomenon change, the inner relation of phenomenon, the subjective cognition of the research object, the interpretation of behavioral meaning, the development and the construction of new theoretical hypothesis. Because the destination is different, they will experience different paths, and the means of transportation needed to reach the destination will be different. It's not hard to see why researchers with two different tools and two different paths can see very different landscapes. But they do ‘see’ and ‘know’ the world in their own way.
 
2. Different research procedures 
From a general sense, all researches follow a general procedure which starts from choosing the research question, research design, data collection, data analysis to achieving the final result in the end. The second is a relatively narrow sense of understanding, which refers to the actual implementation of a variety of different research methods, the specific ‘operating steps’. For example, in the implementation of experimental research, there are specific operational steps such as establishing causal hypothesis, designing experimental environment, recruiting experimental subjects, randomly assigning groups, carrying out pre-experiment test, giving experiment stimulus, carrying out post-experiment test, data statistical analysis, and writing research report. In the implementation of survey and research, there are specific operational steps such as design of sampling plan, actual sampling book, manipulation of variables, the design of questionnaires, distribution and collection of questionnaires, data entry, statistical analysis and writing of research reports.
  The general quantitative aspiration is to eliminate any individual-based subjectivity from the various phases of the research process by developing systematic canons and rules for every facet of data collection and analysis. So the quantitative methodology had gone a long way to standardize procedures to assess objective reality, which ensures they remain stable across investigators and subjects. The quantitative inquiry is systematic, rigorous, focused, and tightly controlled, involving precise measurement and producing reliable and replicable data that is generalizable to other contexts. ( Zoltan Dornyei 2007) 
  However, with the emergent nature of qualitative research, no aspect of the research design is tightly prefigured and a study is kept open and fluid so that it can respond in a flexible way to new details or openings that may emerge during the process of investigation. (Zoltan Dornyei 2007) So in the research process, the qualitative researchers do not set out to test some kind of preconceived hypotheses, but narrow down gradually and define the analytic concepts during the process of the research. Glaser and Strauss (1967) actively encouraged qualitative researchers to ignore the literature before the investigation in order to assure that ‘the emergence of categories will not be contaminated by concepts more suited to different areas’ (p. 37)

3. Different research strategies
Social phenomena are complex and different social phenomena are interrelated. In the face of this complexity and interconnectedness, the main strategy and guiding ideology of quantitative research can be said to be ‘to simplify’. That is, through necessary ‘cutting’, ‘abridging’, ‘trimming’ and ‘simplifying’, the originally complicated society is finally transformed into several key variables, and upon which the research hypothesis is presumed and the research is carried out. Whether to describe or explain the correlation between different phenomena, or focus on certain causal relationship between core variables; and whether it is the most common form of large-scale survey, or relatively rare but more rigorous experiment, or content and the existing statistical data analysis, all of these quantitative research approaches are based upon or connect with these simplified, and limited variables. Even in the use of various multivariate statistical analysis methods of quantitative research, limited variables are dealt with.
 
On the contrary, the main strategy and guiding ideology of qualitative research is different. The goal of qualitative research is not to reduce complexity by decompositing phenomena into variables, but to increase complexity by including contextual factors in the analysis. So, in a sense we can say that the qualitative research is in the ‘expansion of simplicity to complexity’, through the detailed study of the specific situations in reality, the specific background of time and space, the specific social interaction to observe, to study, to understand, to interpret and to achieve the goal of truly knowing the particular social phenomenon. To some extent, this strategy and thinking of qualitative research actually means to change the ‘relatively simple’ phenomenon into ‘relatively complex’ phenomenon, or expand the ‘rather complex’ phenomenon into "more complex" phenomenon. Through these flexible and emergent research strategies, the rich data obtained can widen the scope of our understanding and can add depth to the analysis of a phenomenon. Duff (2002) emphasizes that instead of seeking a generalizable ‘correct interpretation’, qualitative research aims to broaden the repertorie of possible interpretations of human experience. This kind of flexibility also allows us to accept the changes and lead to more exciting results. While under a quantitative research design, unexpected events may draw the whole research result pointless.
 
During the process of ‘expansion of simplicity to complexity’, qualitative research correlates its diversity in research methods to the complexity of the society, namely keeps the integrity and the complexity of the research object in the study as much as possible and maintains the relevance of the research object with a variety of factors. Keeping a state of reality to the largest extent, explore and understand the research phenomena from all-round, multi-angle perspective. In order to do this, qualitative research must keep itself open, flexible and diverse in methods and procedures. However, due to the much emphasis on researchers’ role in qualitative researches, in order to ensure the flexibility of research procedures, integrity and complexity of research phenomena and the depth of investigation, qualitative researchers might have to sacrifice the scope of research phenomena, limit the research in a relatively small field and restricted small number of cases.
 
4. Different research tools
In the quantitative study, in order to guarantee objective research process, achieve valid, reliable and replicable results, and find general overall characteristics of social phenomenon, mutual relations between the variables, the researchers often need to study the phenomenon of strict and standardized sampling, measurements which conform to the requirements of the statistical analysis, also need to use various research tools of high reliability. For data analysis, statistical analysis methods based on mathematical statistics and special statistical analysis software such as SPSS and SAS are needed to draw the research conclusion.
 
In qualitative research, what researchers pursue is not the above goals pursued by the quantitative research, but a deep understanding of specific research objects and social phenomena in specific situations, especially ‘from the inside’. Therefore, on the one hand, in order to better cope with and adapt to the diversity and complexity of research objects and social phenomena; On the other hand, in order to better and more effectively understand the research objects, especially their subjective cognition from the perspective of the research objects, qualitative research can only take the researchers themselves as the main research tool. This characteristic of ‘taking the researcher as a research tool’ comes from the need of qualitative research for ‘empathic understanding’ and ‘person-to-person understanding’. It also comes from the need of qualitative research to participate in real social life, ‘hearing and seeing’, ‘putting oneself in others’ shoes’, and experiencing on the spot. In other words, only by ‘using the researcher himself as a research tool’ can qualitative research properly and freely face the changeable and complicated social phenomena, understand the behaviors in different situations, and especially understand these behaviors from the perspective of the research object.
 
Qualitative research has the strengths in its exploratory nature, making sense of complexity, answering ‘why’ questions, broadening understanding, longitudinal examination of dynamic phenomena, flexibility when things go wrong and rich material for the research report. But there are also some weakness embedded in the issue of sample size and generalizability, role played by the researcher in analyzing the data, lack of methodological rigour, too complex or too narrow theories and time consuming or labour-intensive. (Zoltan Dornyei 2007) research makes the qualitative research more influenced by the researcher's subjective experience, which are especially doubted in two points. First, the qualitative researchers participate in the daily life of the research object directly, frequently and for a long time. This practice will indeed have a firmer sense of ‘seeing is believing’ and ‘empathy’ than quantitative research. But we should also be aware that this kind of reality is in essence a ‘reality as seen by my eyes’, not any ‘reality as seen by the eyes of others’. This ‘empathy’ is a ‘feeling of myself,’ may not be the common feeling by everybody. Therefore, the way in which the researcher collects data is a subjective and specific way, or it is a kind of experience or reality the researcher perceived under a certain time and space circumstances, which inevitably limits the vision and understanding of research phenomena, and naturally leads to the lack of objectivity of qualitative research. This is also what is named as the absence of ‘universal truth’ in qualitative researches.
 
The other is the application of the researcher as a research tool makes the subjective factors of the researcher, such as accomplishment, mental quality, vision, observation ability, communication ability and especially understanding, become particularly important in the research. At the same time, it also makes the degree of qualitative research affected by researchers’ subjective bias more seriously. In quantitative research, the procedures are fixed, the tools are standard and reliable, and the operations of the methods are formatted. Although there are still many aspects in the design and implementation of research that depend on the individual level, ability and accomplishment of researchers, the quality of research done by different researchers and the level of results will also vary. However, in the general operation level, the research mode and process of different researchers are basically similar and replicable. The differences between them are relatively small.
 
In qualitative research, the picture is very different. The differences between the researchers will not only be reflected in the proposed research question and research scheme, the interpretation of the results on the general level, and will also be reflected in the participant observation, case interview, data analysis and other methods and technical level, will be reflected in the way of how to treat research participants, how to communicate with people and take the field notes and many other small, more specific operational aspects. The limitation or incompetence of researchers will not only affect the quality of a qualitative study, even to a certain extent will determine the success or failure of qualitative research and the validity and reliability of the results.
 
The integration of qualitative research and quantitative research
Since both qualitative research and quantitative research have limitations in exploring social phenomena, scholars have been discussing the combination of qualitative research and quantitative research under a variety of names, such as multitrait-multimethod research, interrelating qualitative and quantitative data, methodological triangulation, multi-methodological research, mixed model studies, and mixed methods research ( Creswell et al. 2003). Miles and Huberman (1994:310) summarized the new emerging Zeitgeist as the following:
Entertain mixed models. We have sought to make a virtue of avoiding polarization, polemics, and life at the extremes. Quantitative and qualitative inquiry can support and inform each other. Narratives and variable-driven analyses need to interpenetrate and inform each other. Realists, idealists, and critical theorists can do better by incorporation other ideas than by remaining pure. Think of it as hybrid vigour. Can qualitative and quantitative research be combined? In other words, is ‘hybrid research’ feasible?
 
To answer this question, it is necessary to review the hierarchical model of research design. Some scholars have pointed out that the research design contains four aspects: (1) epistemology (such as objectivism, subjectivism etc.); (2) theoretical perspectives (such as positivism, post-positivism, hermeneutics, critical theory etc.); (3) methodology (such as experimental research, investigation research, ethnographic research, etc.); (4) specific methods (such as questionnaire, interview, experimental and quasi-experimental studies, etc.) （Creswell 2003）Qualitative research and quantitative research are different from each other at the above four levels, and the differences are borne in nature. The more abstract and fundamental or essential aspects the differences lie in(such as epistemology and theoretical perspective), the less likely the integration of the two will be. Concerning the concrete differences (methodology, specific methods) in the operational or instrumental level, the combination of the two is relatively possible. It is based on this characteristic that this essay only analyzes the combination of the two at the level of methodology and specific research methods. When discussing whether the two can be combined and how to combine, we should first discuss and think about the following two questions: first, The so-called combination of qualitative research and quantitative research, does it mean that two different research methods of qualitative research and quantitative research are used simultaneously in a study, or does it mean that some specific methods or techniques of qualitative research and quantitative research are used simultaneously and equally in a study? In other words, at what level (in terms of research methodology or just in terms of specific methods and techniques) does the combination mean? Obviously, the combination of the two at different levels has different practical significance and research effects. The second is will there be a differentiation of primary and secondary between these two research methods in the combination of the two? Are they of equal importance or it is the relationship of primary and secondary? Then who is usually the primary and who is the secondary?
 
The first common case is that researchers use some specific methods and techniques of qualitative research in the process of quantitative research. For example, before conducting systematic, large-scale quantitative investigation of a certain social phenomenon, researchers may conduct some preliminary exploration of this phenomenon by adopting a certain way of qualitative research, such as participation observation, in-depth interview and so on. For example, before designing the questionnaire, researchers usually conduct some open case interviews to understand the basic situation and behavior and attitude characteristics of the respondents, so as to lay a foundation for the design of the questionnaire and make a definite preparation. Some scholars believe that such a situation is called the combination of fixed quantity research and qualitative research in stages, some others believe that such a practice is not actually called the combination of quantitative research and qualitative research, but can only be called the use of some qualitative research methods or techniques in the process of quantitative research. Because this kind of exploratory research are in fact one of the necessary steps in the process of quantitative research. In other words, this open interview is also a tool in the process of quantitative research and a component of quantitative research. In the whole research process, quantitative research (such as investigation research, experimental research, etc.) is obviously different or irrelevant from qualitative research in terms of research objectives, logical thinking, data properties and analytical tools. If this kind of open-ended interview must be regarded as the content of qualitative research, then this combination can only be described as the specific method or technique of slightly combining qualitative research under the premise of taking quantitative research as the main body.
 
The second case is that in quantitative research, researchers do use a specific way and method of qualitative research to help them understand and interpret the results of statistical analysis in quantitative research. This method is called the primary and secondary form by some scholars. Generally speaking, in most cases, the contents of some qualitative research methods are combined in the process of quantitative research as an aid to the analysis or interpretation of quantitative research results. For example, after quantitative questionnaire survey of large-scale objects, in-depth interviews are conducted on a few cases, and the interview results are used to help understand and explain the meaning of quantitative statistical analysis results, or to supplement, verify and explain the former. This is one of the more common approaches to real-world research. On the contrary, in the process of qualitative research, in some case study it is likely to use small questionnaire survey method to collect quantitative information and material, used to describe the characteristics of different objects in the group, or collect some official statistics as case background description, as qualitative research with quantitative research method of auxiliary are rare. Although occasionally some researchers try to convert the data collected by qualitative research into data that can be used for statistical analysis by computer software, this idea might be fundamentally incorrect. Because it violates some basic assumptions and philosophical basis of qualitative research, it is actually equivalent to using the paradigm and standard of quantitative research to ‘cut’ and ‘repair’ the data of qualitative research, and the result may be more fuzzy and invalid.
 
In the third case, different aspects of the overall research problem, or different sub-problems of the central research problem are discussed by using qualitative research and quantitative research respectively. Or for different topics in a large research project, use qualitative research and quantitative research to carry out the research, and use the results of different research methods to answer different aspects of the central question, answer different parts of the overall question, and finally complete the task of answering the central question or the overall question together. This is a practical implement of combination of two research methods. The essence of the combination of the two in the real sense is as follows: qualitative research and quantitative research are two different ways to answer questions of different properties respectively.
 
In the combination of the two methods, we should consider and choose the research methods based on the need to answer the research questions. If your research problem is only suitable for a certain research method, do not impose two different research methods (this practice is neither feasible nor effective).If the nature of the research problem is only suitable for the use of qualitative research, do not use quantitative research, and vice versa. From the perspective of research design, the selection of research methods is also a trade-off. Researchers need to weigh between different research objectives, between different types of observations, and between different tools used for descriptive reasoning and causal reasoning. There is only one selection standard for qualitative research methods, quantitative research methods, or combination of the two, that is, the suitability of answering the research questions. The most appropriate research methods should be selected and adopted to achieve the research objectives and the best research results.

References:
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Duff, P. ‘Research approaches in applied linguistics’ in R. B. Kaplan (ed.). The Oxford Handbook of Applied Linguistics. (New York: Oxford University Press, 2002)
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