Qualitative and quantitative research

Quantitative and qualitative research are the two dominant research paradigms or methodologies used in the human and social sciences. Both quantitative and qualitative research are modes of inquiry that use different methods to acquire answers to social phenomena. Purists believe that researchers who use either the quantitative or qualitative approach to research look at how the world is viewed and what is important to know differently from one another. Onwuegbuzie and Leech (2005) state that there are those in the research world who do not advocate the mixing of these two research methods. Researchers who consider themselves pragmatists advocate integrating methods within a single study. Sieber (1973) states that researchers can utilize the strengths of both methodologies in any given study in order to understand social phenomena. There has been a growth in the mixing of quantitative and qualitative approaches in the twenty-first century, as researchers look to all available research techniques to address the research questions, rather than promote a preconceived bias toward one methodology or another. This is referred to as a mixed methods design.

Keywords Data; Dependent Variable; Experiment; Factor; Independent Variable; Modes of inquiry; Qualitative Data; Quantitative Data; Pragmatic researcher; Reliability; Research methods; Surveys; Theory; Triangulation; Validity

Overview

Quantitative and qualitative research are the two dominant research paradigms, or methodologies, used in the human and social sciences. Both quantitative and qualitative research are modes of inquiry that use different methods to acquire answers to social phenomena. Purists advocate a mono-method, a single approach to research. Purists believe that researchers who use either the quantitative or qualitative approach to research look at how the world is viewed and what is important to know differently from one another. Onwuegbuzie and Leech (2005) state that there are those in the research world who do not advocate the mixing of these two research methods. However, Onwuegbuzie and Leech (2005) further assert that the choice of research methodology should be dependent upon the research questions. Researchers who consider themselves pragmatists advocate integrating methods within a single study. Sieber (1973) states that researchers can utilize the strengths of both methodologies—quantitative and qualitative—in any given study in order to understand social phenomena. As Miles and Huberman (1984) state, "Epistemological purity doesn't get research done" (p. 21). To pragmatists, research methodologies are "merely tools that are designed to aid our understanding of the world" (Onwuegbuzie & Leech, 2005, p. 376).

Quantitative Research

The philosophical framework for quantitative research (often called the traditional, positivist, experimental, or empiricist paradigm) is based on the empiricist tradition established by such authorities as Comte, Mill, Durkheim, Newton, and Locke. To a positivist researcher, reality is objective and independent of the researcher. Research is formal, value-free, and unbiased. There are two types of quantitative methodologies: experiment or survey. The process itself is deductive in nature, with a cause-effect approach to the research. The researcher generalizes, leading to predictions, explanations, and understandings. Accuracy, or validity, and consistency, or reliability, are critical for all research, including quantitative research. According to positivists, since pure quantitative methodologies are objective in nature, if any part of the research possesses a subjective element, then any interpretation of the data must be ultimately subjective.

Variables

The components of quantitative research include measuring subjects and reporting the results. Experiments test the cause and effect of the sample population. The researcher identifies independent variables, called treatment conditions or factors in an experiment. Rosenthal and Rosnow (1991) identify five examples of independent variables:

• Biological events (such as food deprivation);

• Social environments;

• Hereditary factors;

• Previous training and experience; and

• Maturity.

Dependent variables are also identified and are described by Creswell (1994) as "the responses or the criterion variables presumed to be "caused" or influenced by the independent variable" (p. 129).

These examples of independent variables are only a small sampling of the possible independent variable possibilities in research. The research design provides a description of a random representation of the population, or the sample. In other words, the study outlines the selection of subjects and how many will participate in the experiment. The researcher states how the random sample will be selected.

Collecting Data

Random sampling allows the researcher to generalize the findings of the study to an entire population. The researcher carefully designs the data instrument, giving a rationale for its selection as a tool for collecting data. The instrument can be one that the researcher designed themselves, an instrument that the researcher can modify that has been used in another study, or an intact instrument that has been used by another researcher. Permission must be acquired before a researcher uses an instrument that has been used in a previous research study. A pre-existing instrument should already have an established validity and reliability. Creswell (1994) states that "during an experiment, a researcher makes observations or obtains measures by using instruments at a pre-test and post-test stage" (p. 129). Researchers create treatment conditions and develop a step-by-step procedure for conducting the experiment.

Qualitative Research

Qualitative research is based on a constructivist or naturalist approach and began as a countermovement to the positivist paradigm. To the qualitative researcher, reality is subjective and seen through the eyes of the participants in the study. The researcher interacts with the subjects through the emerging design of the research project. The process is inductive in nature, and patterns or theories are developed through the research process. Creswell (1994) outlines four qualitative research designs that are frequently found in human and social science research:

• Ethnographies, in which a researcher studies a cultural group in a natural setting during a specified period of time;

• Grounded theory, in which a researcher develops a theory through multiple stages of data collection and compares it with other theories found in the literature;

• Case studies, in which a researcher explores a single phenomena that occurs during a defined time or activity and collects data; and,

• Phenomenological studies, in which a researcher examines a human experience through detailed descriptions.

Perceived Differences Between Quantitative & Qualitative Research

Gall, Borg, and Gall (1996) have developed an outline of the assumed differences between quantitative and qualitative research, which are as follows:

• Quantitative researchers view causal relationships among social phenomena from a mechanistic perspective, while qualitative researchers assign human intentions a major role in explaining causal relationships among social phenomena.

• Quantitative researchers assume an objective social reality, whereas qualitative researchers assume that social reality is constructed by the participants.

• Quantitative researchers assume that social reality is relatively constant across time and settings, whereas qualitative researchers assume that social reality is continuously constructed in social situations.

• Quantitative researchers take an objective, detached stance towards research participants and their setting, whereas qualitative researchers become personally involved with research participants.

• Quantitative researchers study populations or samples that represent populations, while qualitative researchers study cases.

• Quantitative researchers study behavior and other observable phenomena, while qualitative researchers study the meanings that individuals create and other internal phenomena.

• Quantitative researchers study human behavior in natural or contrived settings, while qualitative researchers study human actions in natural settings.

• Quantitative researchers use preconceived concepts and theories to determine what data will be collected, while qualitative researchers discover concepts and theories after data have been collected.

• Quantitative researchers generate numerical data to represent the social environment, while qualitative researchers generate verbal and pictorial data to represent the social environment.

• Quantitative researchers use statistical methods to analyze data, whereas qualitative researchers use analytic induction to analyze data.

• Quantitative researchers study human behavior in natural or contrived settings, while qualitative researchers study human actions in natural settings.

• Quantitative researchers use statistical inference procedures to generalize findings from a sample to a defined population, whereas qualitative researchers generalize case findings by searching for other similar cases.

• Quantitative researchers prepare impersonal, objective reports of research findings, while qualitative researchers prepare interpretative reports reflecting researchers' constructions of the data and an awareness that readers will form their own constructions from what is reported.

Combining the Two Methods

For pragmatists who advocate that the research question drives the choice of research methodology, the mixing of quantitative and qualitative methodologies is a possibility in any given study. Sechrest and Sidani (1995) and others provide a list of similarities between quantitative and qualitative methodologies. Both quantitative and qualitative processes:

• Involve the use of observation to address research questions. Both methodologies "describe their data, construct explanatory arguments from their data and speculate about why the outcomes they observed happened as they did" (Sechrest & Sidani, 1995, p. 78).

• Use techniques that are relatively analogous at some level of specificity, such as triangulation.

• Try to discover meaning from the interpretation of data.

• Use analytical techniques in an attempt to explain complex relationships in the social science world.

• Utilize techniques to verify their data.

• Use data reduction as an important part of the data analysis process.

• Promote the role of theory by testing theory (quantitative methods) or initiating and building theory (qualitative methods).

• Can use the same collection of data to get results.

There has been a growth in the mixing of quantitative and qualitative approaches in the twenty-first century, as researchers look to all available research techniques to address the research questions, rather than promote a preconceived bias toward one methodology or another.

Further Insights

Exemplary Manuscript Guidelines

Smart (2005) states that research manuscripts need to advance the development of knowledge or inform institutional policy. In order for research to have this sort of impact, research manuscripts need to have many strong characteristics. Exemplary manuscripts are balanced in form and include:

• One-third introduction and literature review that includes complex and important topics facing scholars and policymakers and the state of current knowledge about those topics,

• One-third research procedures and findings, which includes the sampling design, research design, measurement, statistics, and the proper reporting of research evidence obtained, and,

• One-third discussion and implications, which encompasses synthesis and integration of findings obtained from the present investigation within the context of existing knowledge.

A Literature Review is a review of the literature that informs the research project. The literature review presents a theoretical background and a review of other studies that are closely related to the study that the researcher is developing; makes connections to the dialogue about the topic that may be appearing in literature; provides a framework for the researcher's study; and acts as a benchmark for findings that the research will reveal.

Typical Qualitative Research Project Format

Vivar, McQueen, Whyte, and Armayor (2007) outline the steps that a researcher may take in developing a qualitative research project. These steps include:

• Selecting an interesting topic;

• Conducting a literature review to identify what has already been written about the topic, including

• The description of practice-based research, systematic reviews, literature reviews, and meta-analysis;

• Presenting the significance of the study by clarifying why the research is important, through the writing of a proposal;

• Defining the concepts in the study;

• Finding a theoretical framework;

• Choosing a method of data collection, whether these be interviews, focus groups, and/or observations;

• Planning the data collection, including running a pilot study to prevent unexpected problems and to

• Identify modifications necessary in the full study;

• Describing the procedures of data analysis, with a justification of procedures to be used in the study;

• Enhancing the quality of the study, including presenting an in-depth description of the project, how and

• What decisions are made and any issues that occur throughout the study;

• Reporting the ethical issues; including potential risks;

• Illuminating the limitations of the study;

• Disseminating the findings, by sharing the results of the research with other professionals through

• Presenting in professional academic journals, conferences, seminars, and other meetings where

• Professionals gather in conversation about research;

• Planning the timeframe, or the time it takes to complete the study;

• Concluding, highlighting the major elements of the study; and, finally,

• Presenting the references, or the bibliography.

Typical Quantitative Research Project Format

Creswell (1994) outlines a typical quantitative research project format, including the following segments:

• Introduction:

• Context (Statement of the problem)

• Purpose of the study

• Research questions or objectives or hypothesis

• Theoretical perspective

• Definition of terms

• Delimitations and limitations of the study

• Significance of the study

• Review of the Literature:

• Methods:

• Research design

• Sample, population, or subjects

• Instrumentation and materials

• Variables in the study

• Data analysis

• Appendices:

• Instruments

Verification of Data

Both quantitative and qualitative data can be verified, using different techniques. Quantitative research can be verified "through a control process and random sampling techniques to maximize internal and external validity" (Onwuegbuzie & Leech, 2005, p. 380). Qualitative verification methodologies include:

• Triangulation;

• Prolonged engagement;

• Persistent observation;

• Leaving an audit trail;

• Member checking;

• Weighing the evidence;

• Checking for representativeness of sources of data;

• Checking for researcher effect;

• Making contrasts and comparisons;

• Checking the meaning of outliers;

• Using extreme cases;

• Ruling out spurious relations;

• Replicating a finding;

• Assessing rival explanations;

• Looking for negative evidence;

• Obtaining feedback from informants;

• Peer debriefing;

• Clarifying researcher bias; and

• Thick description.

Viewpoints

Absence of Sound Theory

Some researchers believe modern research lacks sound theory and does not significantly contribute to the field of knowledge. Smart (2005), for example, asserts that "reliance on strong theories is a rare attribute of higher education research manuscripts." He states that "the focus seems to be more toward development of our own distinct intellectual heritage and less toward reliance on the intellectual traditions of the more mature and advanced academic disciplines" (p. 468). He mentions three benefits to including sound theory in any research. Sound theories:

• Provide a roadmap by identifying the important variables to be included in studies and the hypothesized relationships among those variables;

• Incorporate extant empirical findings within a logical and consistent framework; and,

• Offer a coherent potential answer to important issues facing the academic community.

Advantages of Pragmatic Research

Onwuegbuzie and Leech (2005) state that there are definite advantages to becoming a pragmatic researcher as opposed to a researcher who is wedded to either quantitative or qualitative research. They state that pragmatists who use a dual approach to research:

• Are flexible in their investigative techniques, as they attempt to address a range of research questions that arise;

• Promote collaboration among researchers;

• View research as a holistic endeavor;

• Can use quantitative research to inform qualitative research, and vice versa;

• Can combine macro and micro approaches to viewing data;

• Can merge two voices, the researcher and the participant.

Calls for More Qualitative Research Studies

Naidoo and Orme (1998) state that qualitative research studies need to be included more in research journals, particularly in health literature. Predominantly, journals lean toward publishing quantitative research, as it has long been considered to have more rigorous methodology. Rogers, Popay, Williams and Latham (1997) state that "there is a role for qualitative research in illuminating further the vital link between human agency and structural context in people's lives" (p. 31). While fewer qualitative studies appear in journals than quantitative studies, Naidoo and Orme (1998) point out that qualitative research is ideal in health care research, as qualitative research "is likely to comprise smaller scale studies and hence be less expensive than larger quantitative studies" (p. 94). However, qualitative research is often excluded from journals because the studies do not conform to what are perceived to be scientific standards.

Terms & Concepts

Data: Data are "the scores or numerical measurements of behavior or characteristics obtained from observations of a sample of people or animals" (Kiess, 1996, p. 538).

Dependent Variable: A dependent variable is "a variable in an experiment that depends on the independent variable; in most instances, the dependent variable is some measure of a behavior" (Kiess, 1996, p. 538).

Experiment: An experiment is "a controlled situation in which one or more independent variables are manipulated to observe the effect on the dependent variable" (Kiess, 1996, p. 538).

Factor: A factor is another name for an independent variable.

Independent Variable: An independent variable is "a variable manipulated in an experiment to determine its effect on the dependent variable" (Kiess, 1996, p. 539).

Qualitative Data: Qualitative data are "data obtained from nominal measurement indicating that variables differ in quality" (Kiess, 1996, p. 541).

Quantitative Data: Quantitative data are "data obtained from ordinal, interval, or ratio measurements, indicating how much of a variable exists" (Kiess, 1996, p. 541).

Reliability: Questions that support the efforts by researchers to establish reliability are:

• Are the item responses consistent across constructs? (item consistency)

• Do individuals vary in their responses when the instrument is measured a second time? (test stability)

• Were errors caused by carelessness in administration or scoring? (consistency in test administration and scoring).

Surveys: Surveys are cross-sectional or longitudinal studies using questionnaires or structured interviews for data collection with the intent of generalizing from a sample to a population.

Theory: Kerlinger (1986) defines theory as "a set of interrelated constructs (concepts), definitions, and propositions that present a systematic view of phenomena by specifying relations among variables, with the purpose of explaining and predicting the phenomena" (p. 9).

Triangulation: Triangulation occurs when a researcher "seeks convergence and corroboration of results from different methods...as he/she studies the same phenomena" (Onwuegbuzie, 2005, p. 384). In quantitative data, researchers might triangulate several measures of achievement; in qualitative data, researchers might triangulate interview data with observational data.

Validity: Creswell (1994) defines the many types of validity through effective questions. These questions support the efforts by researchers to establish validity:

• Do the items measure the content they were supposed to measure? (content validity)

• Do scores predict a criterion measure? (predictive validity)

• Do results correlate with other results of similar tests? (concurrent validity)

• Do items measure the hypothetical constructs or concepts the study intended to measure? (construct validity)

• Do the items appear to measure what the instrument purports to measure? (face validity) (p. 121).

Variable: Kiess (1996) defines a variable as "any environmental condition or event, stimulus, personal characteristic or attribute, or behavior that can take on different values at different times or with different people" (p. 543).

Testing noncognitive constructs using quantitative or qualitative methods, such as attitudes in the workplace or depression, in the twenty-first century, The Standards for Educational and Psychological Testing (2014), often called “The Standards” in the social sciences, is the primary reference for guidance of validity and reliability. This reference was created by the American Educational Research Association (AERA), American Psychological Association (APA), and National Council on Measurement in Education (NCME) to better standardize qualitative testing in social science research and to address the proliferation of validity and reliability definitions.

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