Qualitative and Quantitative Research Designs

Psychological research can be approached in two ways- through a qualitative study or a quantitative study – depending on the type of problem the researcher needs to research.  The researcher’s choice of one of these approaches will shape the procedures to be use in each step of the research process.

Definitions

            To understand the differences and similarities between quantitative and qualitative approaches, a researcher should consider definitions of the terms quantitative and qualitative research. Quantitative research is a type of research in which the researcher decides what to study, asks specific, narrow questions, and collects numeric (numbered) data from participants, analyzes these numbers using statistics, and conducts the inquiry in an unbiased, objective manner.

Qualitative research on the other hand, is a type of educational research in which the researcher relies on the views of participants, asks broad, general questions, collects data consisting largely of words (or text) from participants, describes and analyzes these words for themes, and conducts the inquiry in a subjective, biased manner (American Psychological Association, 2001).

Aside from these two definitions, there are more differences and similarities between quantitative research and qualitative research according to the steps involved in psychological research.  But first, the similarities and differences will become clearer if the historical high points in the development of each approach will be explored.

The 20th century began with one major approach to educational research—quantitative research— and ended with two major approaches—quantitative and qualitative research. The development of the two approaches is not a case of one approach replacing the other; instead, it reflects the addition of qualitative inquiry to the traditional quantitative approach (Swanborn, 1996).

With different historic origins, it is little wonder that quantitative and qualitative research differ. Relating each approach to the six steps in the process of research helps a researcher understand these differences. By closely examining each step, one will see that researchers apply the two approaches differently at each step (Tashakkori, et al., 1998).

Differences and Similarities of Quantitative and Qualitative research

Identifying a Research Problem

In quantitative research, describing a trend means that the research problem can be answered best by a study in which the researcher seeks to establish the overall tendency of responses from individuals and to note how this tendency varies among people. For example, researchers might seek to learn how voters describe their attitudes toward a bond issue (Ward, 1992). Results from this study can inform how a large population views an issue and the diversity of these views. However, some quantitative research problems require that you explain how one variable affects another. Variables are an attribute (e.g., attitude toward the school bond issue) or characteristic of individuals (e.g., gender) that researchers study. By explaining a relationship among variables, researchers are interested in determining whether one or more variables might influence another variable. For example, the authors in the television violence study (Vooijs & van der Voort, 1993) described trends on test scores and examined the relationship among variables. They recorded the children’s test scores on several instruments, such as “readiness to see violence,” and they described generally how students scored on these instruments. They also studied whether the special curriculum on crime influenced the children’s views toward violence on television. Thus, the study of trend and relationships represented ways the researchers studied the problem of the impact of television violence on children.

Qualitative research, however, is best suited for research problems in which the researchers do not know the variables and need to explore. The literature might yield little information about the phenomenon of study and they need to learn more from participants through exploration. A central phenomenon is the key concept, idea, or process studied in qualitative research. For example, the research problem of the difficulty in teaching children who are deaf requires both an exploration (because we do not know how to teach these children) as well as an understanding (because of its complexity) of the process of teaching and learning (Bryman, 1988).

In a qualitative study such as the gunman case study (Asmussen & Creswell, 1995), the researchers are not interested in explaining the incident; rather, they seek to explore and gain a deeper understanding of how those on campus reacted to the incident. They map the process in all of its complexity as it unfolds during an 8-month period following the incident. This is both exploration and understanding qualitative research study.

Reviewing the Literature

In quantitative research, the researcher will typically see a substantial literature review at the beginning of the study. Thus, the literature plays a major role in two ways: justifying the need for the research problem and identifying the direction of the study. Justifying the research problem means that the researcher use the literature to document the importance of the issue examined in the study. To accomplish this, the researcher search the literature, locate studies that identify the problem as important to examine, and then cite this literature in the opening sections of a research report. The literature also creates a need for the study, as expressed specifically in the purpose statement and the research questions or hypotheses. The researchers identify in the literature key variables, relationships, and trends, and use these to provide direction for the research questions and hypotheses (Carspecken & Apple, 1992). A literature review on college students, for example, may show that we know little about the problem of “binge drinking.” Existing literature, however, may identify the importance of peer groups and styles of interacting among student peer groups. Thus, important research questions might address how peer groups and interaction styles influence binge drinking on college campuses. In this way, the literature in a quantitative study both documents the need to study the problem and provides direction for the research questions.

In qualitative research, the literature review plays a less substantial role at the beginning of the study. Although researchers may review the literature to justify the need to study the research problem, the literature does not provide major direction for the research questions. The reason for this is that qualitative research relies on the views of participants in the study and less on the direction identified in the literature by the researcher. Thus, to use the literature to foreshadow or specify the direction for the study is inconsistent with the qualitative approach of learning from

participants. For example, Cox and Davidson (1995), who are qualitative researchers studied bullying in the schools cited several studies at the beginning of the research to provide evidence for the problem, but did not use the literature to specify the research questions. Instead, this researcher attempted to answer in the research the most general, open question possible, “What is bullying?,” to learn how students constructed their view of this experience. In a similar way, the literature plays a minor role in the qualitative gunman incident study (Asmussen & Creswell, 1995). The article opens with references that support the importance of the problem of campus violence.  But in the next section of the study, the authors describe the incident, and the literature does not reappear until the final passages in the study in which the authors describe the need for campus planning. Hence, in this study, the literature justifies the research problem, but it does not lead to the questions asked in the study. The questions are general, allowing the participants to help construct answers. Thus, in a qualitative study, the literature is of secondary importance while the views of the participants are of primary importance (Carspecken & Apple, 1992).

Purpose for Research

In quantitative research, the researcher asks specific, narrow questions to obtain measurable and observable data on variables. The major statements and questions of direction in a study—the purpose statement, the research questions, and the hypotheses—are specific and narrow because you identify only a few variables to study. From a study of these variables, the researcher obtains measures or assessments on an instrument or record scores on a scale from observations. For example, in a study of adolescent career choices, the variable, the role of the school counselor, narrows the study to a specific variable from among many variables that might be studied (e.g., role of parents, personal investment by student). To examine the impact of the school counselor on adolescent career choices, data must be obtained from the students (Danziger, 1988).

In the quantitative television violence study (Vooijs & van der Voort, 1993), the researchers select (and narrow) their interest to a few variables. They measure the children’s “readiness to see violence” or “approve of violence”. They state specific questions they want answered, such as the types of children who profit most from the lessons in the curriculum on crime. To learn this information, they obtain data from the children by collecting personal information on each child, such as gender, social economic status, grade attended, school achievement, and aggressiveness.

In qualitative research, the purpose is much more open ended than in quantitative research. The researchers ask general, broad questions so that one can best learn from participants. Then research a single phenomenon of interest and state this phenomenon in a purpose statement. A qualitative study by Dijkstra, et al. (1992) examines the “professionalism” of teachers, for example, asks high school teachers, “What does it mean to be a professional?” This question focuses on understanding a single idea, being a professional, and the responses to it will yield qualitative data, such as quotations.

In the qualitative gunman case study (Asmussen & Creswell, 1995), the researchers start with broad, open-ended questions to obtain participants’ views about the incident. This questioning focuses on understanding the process of the campus reaction to the gunman incident. The researchers’ intent is to allow the participants to talk openly about their experiences. For example, examine the authors’ first general, broad question: “What happened?”

Collecting Data

In quantitative research, the researcher uses an instrument to measure the variables in the study. An instrument is a tool for measuring, observing, or documenting quantitative data. It contains specific questions and response possibilities that you establish or develop in advance of the study. Examples of instruments are survey questionnaires, standardized tests, and checklists that you might use to observe behaviors among participants. The researchers administer this instrument to the participants, and collect data in the form of numbers. For instance, he might collect responses based on students checking boxes on a form, or from checklists you complete as you watch a student perform a task in the classroom. The intent of this process is to apply the results (called generalizing the results) from a small number of people to a large number.

The larger the number of individuals studied, the stronger is the case for applying the results to a large number of people. For example, on a survey research (Marsh, 1992), the researcher sent to 500 parents in a school district, the researcher seeks information about parents’ attitudes toward the educational needs of pregnant teenagers in the schools. The researcher selects an instrument, “Attitudes Toward Education of Pregnant Teenagers,” found through a search of library resources. The 500 parents who receive this instrument represent a cross section of people from all socioeconomic levels in the school district. After collecting and analyzing this data, the investigator will draw conclusions about all parents in this school district based on the representative sample studied. Data collection is also an integral part of the quantitative television violence study (Vooijs & van der Voort, 1993). The authors study a large number of children (221 in the experimental group and 216 in the control group) in six different schools. They examine these large numbers of children so that they can obtain a good cross section of the students in the six schools. In addition, the authors identify instruments for assessing the children’s views toward television violence before the study begins. One instrument, for example, is the “Readiness to See Violence,” a test consisting of 25 violent actions. On this instrument, the children rate their reactions to television violence, yielding numeric scores in the study.

In qualitative research, the researcher does not begin data collection with a preestablished instrument to measure distinct variables. Instead, he seeks to learn from the participants in the study, and develop forms, called protocols, for recording data as the study proceeds. These forms pose general questions so that the participants can provide answers to the questions. Often questions on these forms will change and emerge during data collection. Examples of these forms include an interview protocol, which consists of four or five questions, and an observational protocol, in which the researcher records notes about the behavior of participants. Moreover, you gather text (word) or image (picture) data. Transcribed audio recordings form a database composed of words. Observing participants in their work or family setting, you take notes that will become a qualitative database. When researchers ask young children to write their thoughts in a diary, these diary entries become a text database. With each form of data, you will gather as much information as possible to collect detailed accounts for a final research report (Sieber, 1993).

In the qualitative gunman case study (Asmussen & Creswell, 1995), the researchers collect data from a few individuals on campus representing different constituents (e.g., administrators, counselors, “experts”).  They do not use instruments constructed by other researchers; instead, they develop their own forms for recording information—an interview protocol—during the project. This form contains general questions so that the constituents can provide their own responses to the questions. They also take observational notes about the classroom in which the incident occurred and collect campus newspaper reactions to the crisis.

Analyzing and Interpreting Data

In quantitative research, the researcher analyzes the data using mathematical procedures, called statistics. These analyses consist of breaking down the data into parts to answer the research questions. Statistical procedures, such as comparing groups or relating scores for individuals, provide information to address the research questions or hypotheses. He then interprets the results of this analysis in light of initial predictions or prior studies. This interpretation is an explanation as to why the results turned out the way they did, and often you will explain how the results either support or refute the expected predictions in the study (Carspecken et al., 1992).

For example, in the quantitative television violence study (Vooijs & van der Voort, 1993), the researchers collect responses from the children and assign numbers to each child’s score. They mathematically examine the numerical differences between the group that experiences the curriculum and the group that does not, in terms of the children’s views toward television violence. They examine this difference using statistical procedures, such as analysis of covariance. The researchers conclude the article with a discussion that compares their results with results from other studies. They suggest that their positive results may be partly due to the “reality content” of their lessons—an improved feature of their lessons that other authors did not consider (Vooijs & van der Voort, 1993).

In qualitative research, because the data consists of words or pictures, a different approach exists for data analysis. Typically, researcher gathers a text database, so the analysis of text consists of dividing it into groups of sentences, called text segments, and determining the meaning of each group of sentences. Rather than using statistics, you analyze words or pictures to describe the central phenomenon under study. The result may be a description of individual people or places. In some qualitative studies, the entire report is mostly a long description of several individuals. The result may also include themes or broad categories that represent your findings. In qualitative studies in which you both describe individuals and identify themes, a rich, complex picture emerges. From this complex picture, you make an interpretation of the meaning of the data by reflecting on how the findings relate to existing research, by stating a personal reflection about the significance of the lessons learned during the study, or by drawing out larger, more abstract meanings (Carspecken et al., 1992).

The authors of the qualitative gunman case study use these analysis and interpretation procedures (Asmussen & Creswell, 1995). They review their text data consisting of transcripts from interviews, written notes from observations, and documents, including newspaper accounts. They also have a videotape of a news conference filmed immediately after the incident. From this data (both words and images), the authors first describe chronologically the events for two weeks following the incident. They then identify themes or categories such as “Denial.” Other themes mentioned were safety and campus planning. Finally, in the discussion at the end of the article, the researchers interpret the broader meaning of their description and themes, mentioning that the theme fits into larger psychological and social-psychological social science perspectives. In the epilogue, the authors introduce themselves into the study by commenting about the personal meaning of the incident. Qualitative researchers typically bring themselves directly into the written report in some way, such as writing an epilogue, writing about their experiences when they discuss the procedures, or weaving their personal experiences into the conclusion (Denzin, et al., 2000).

Reporting and Evaluating Research

In quantitative research, the overall format for a study follows a predictable pattern: introduction, review of the literature, methods, results, and discussion. This form creates a standardized structure for quantitative studies. In addition, it also leads to specific criteria that a researcher might use to judge the quality of a quantitative research report. For example, a researcher examine a quantitative study to see if it has an extensive literature review; tests good research questions and hypotheses; uses rigorous, impartial data collection procedures; applies appropriate statistical procedures; and forms interpretations that naturally follow from the data.

In quantitative research, researchers also use procedures to ensure that your own personal biases and values do not influence the results. They use instruments that have proven value and that have reliable and valid scores from past uses of the instruments. They design studies to control for all variables that might introduce bias into a study. Finally, they report research without referring to themselves or their personal reaction (Bryman, 1988).

However, in qualitative research, researchers employ a wide range of formats to report their studies. Although the overall general form follows the standard steps in the process of research, the sequence of these “parts” of research tends to vary from one qualitative report to another. A study may begin with a long, personal narrative told in story form or with a more objective, scientific report that resembles quantitative research. With such variability, it is not surprising that the standards for evaluating qualitative research also are flexible. Good qualitative reports, however, need to be realistic and persuasive in order to convince the reader that the study is an accurate and credible account. Qualitative reports typically contain extensive data collection to convey the complexity of the phenomenon or process. The data analysis reflects description and themes as well as the interrelation of themes (Bryman, 1988).

Furhter, Bryman (1988) stated that in general quantitative and qualitative research is similar in the following:

1. Both forms of research follow the six steps in the scientific process of research.
2. In the section on the research problem—found in the introduction to a study—both quantitative and qualitative research can be similar in the topics addressed, such as conveying a problem, pointing out the lack of literature on this problem, and justifying a need to study the problem. This does not mean that the type of problem is the same, only the format for reporting the problem.

In both quantitative and qualitative research, you collect data using interviews, observations, and documents. However, later we shall see a difference between the types of interviews or observations used in these two approaches.

Research Designs Associated with Quantitative and Qualitative Research

 It is not enough to know the steps in the process of research, and that quantitative and qualitative procedures differ at each step. The detailed procedures involved in quantitative, qualitative, and combined research must be explored. Research designs are the specific procedures involved in the last three steps of the research process: data collection, data analysis, and report writing. These research designs differ for quantitative, qualitative, and combined research.

Experimental Designs

Some quantitative researchers seek to test whether an educational practice or idea makes a difference for individuals. Experimental research procedures are ideally suited for this study. Experimental designs (also called “intervention studies” or “group comparison studies”) are procedures in quantitative research in which the investigator determines whether an activity or materials make a difference in results for participants. Researchers assess this impact by giving one group one set of activities (called an intervention) and withholding the set from another group (Bausell,1994).

Correlational Designs

In some studies, researchers may be unable to provide an intervention or to assign individuals to groups. Moreover, researchers focus more on examining the association or relationship of one or more variables than in testing the impact of activities or materials. Correlational designs are procedures in quantitative research in which investigators measure the degree of association (or relationship) between two or more variables using the statistical procedure of correlational analysis. This degree of association, expressed as a number, indicates whether the two variables are related or whether one can predict another. To accomplish this, researchers study a single group of individuals, rather than two or more groups as in an experiment (Fisher,1995).

Survey Designs

In another form of quantitative research, researchers may not want to test an activity or materials or may not be interested in the association among variables. Instead, they seek to describe trends in a large population of individuals. In this case, a survey is a good procedure to use. Survey designs are procedures in quantitative research in which researchers administer a survey or questionnaire to a small group of people (called the sample) in order to identify trends in attitudes, opinions, behaviors, or characteristics of a large group of people (called the population) (Babbie, 1990).

Grounded Theory Designs

Instead of studying a single group, researchers might examine a number of individuals who have all experienced an action, interaction, or process. Grounded theory designs are systematic, qualitative procedures that researchers use to generate a general explanation (called a grounded theory) that explains a process, action, or interaction among people. The procedures for developing this theory include collecting primarily interview data, developing and relating categories (or themes) of information, and composing a figure or visual model that portrays the general explanation. In this way, the explanation is “grounded” in the data from participants. From this explanation, researchers construct predictive statements about the experiences of individuals (Becker, 1993).

Ethnographic Designs

A researcher may be interested in studying one group of individuals, in examining them in the setting where they live and work, and in developing a portrait of how they interact. An ethnographic study is well suited for this purpose. Ethnographic designs are qualitative procedures for describing, analyzing, and interpreting a cultural group’s shared patterns of behavior, beliefs, and language that develop over time (Hammersley, &Atkinson, 1995). In ethnography, the researcher provides a detailed picture of the culture-sharing group, drawing on various sources of information. The ethnographer also describes the group within its setting, explores themes or issues that develop over time as the group interacts, and details a portrait of the group (Denzin, 1997).

Narrative Research Designs

A researcher may not be interested in describing and interpreting group behavior or ideas, or in developing an explanation grounded in the experiences of many individuals. Instead, he wishes to tell the stories of one or two individuals. Narrative research designs are qualitative procedures in which researchers describe the lives of individuals, collect and tell stories about these individuals’ lives, and write narratives about their experiences. In education, these stories often relate to school classroom experiences or activities in schools (Clandinin & Connelly, 2000).

Mixed Methods Designs

A researcher may decide to collect both quantitative data (i.e., numbers) as well as qualitative data (i.e., text or images). The combination of both forms of data provides a better understanding of a research problem than one type of data alone. Mixed methods designs are procedures for collecting, analyzing, and linking both quantitative and qualitative data in a single study or in a multiphase series of studies (Brewer & Hunter,1989). In this process, researchers need to decide on the emphasis you will give to each form of data (priority), which form of data you will collect first (concurrent or sequential), how you will “mix” the data (integrating or connecting), and whether he will use an advocacy lens (e.g., feminist or class theories) to guide your study (Bazeley,2000). 

Action Research Designs

Like mixed methods research, action research often utilizes both quantitative and qualitative data, but it focuses more on procedures useful in addressing practical problems in schools and the classrooms. Action research designs are systematic procedures used by teachers (or other individuals in an educational setting) to gather quantitative and qualitative data to address improvements in their educational setting, their teaching, and the learning of their students. In some action research, you seek to address and solve local, practical problems, such as a discipline classroom issue for a teacher. In other studies, your objective might be to empower, transform, and emancipate individuals in educational settings (Atweh et. al., 1998).

Which is Which?

With the differences and similarities of quantitative and qualitative research in mind, as well as the different procedures or designs used to conduct research, how do researchers decide whether to use a quantitative or qualitative (or some combination) approach? Consider three factors described below by Brewer & Hunter (1989).

Match the Approach to the Research Problem

The most important factor that should go into a researchers` decision is to match his quantitative or qualitative approach to the research problem. Remember that the problems best suited for quantitative research are those in which trends or explanations need to be made. For qualitative research, the problems need to be explored to obtain a deep understanding. A combined design seeks both trends or explanations, exploration, and a deep understanding. 

Fit the Approach to Your Audience

A second factor that should be considered involves the audience for whom the researcher is writing the research report. Psychologists write for several audiences, such as policy makers, faculty and graduate committees, editors and review boards, parents, and individuals in educational settings who will read and possibly use the findings from a study. It is important that the audience(s) be familiar with the approach used in a study. Quantitative research may be more familiar to psychologists today who are trained in experimental research, survey designs, and statistical procedures. However, qualitative research now draws a substantial following, and through books, articles, conferences, and workshops, educators can obtain a much firmer grasp of qualitative inquiry than they could a few years ago.

Relate the Approach to Your Experiences

Choose an approach based on personal experiences and training. Conducting research in either quantitative or qualitative research requires skills in conceptualizing research, conducting research, and writing the study. A quantitative researcher typically has taken some courses or training in measurement, statistics, and quantitative data collection approaches, such as experimental, correlational, or survey techniques. Qualitative researchers need experience in field studies in which they practice gathering information in a setting and learn the skills of observing or interviewing individuals. Course work or experience in analyzing text data is also helpful. Thus, the choice of approach must relate to the personal skills, training, and experiences of the researcher.

In conclusion, psychologists use either quantitative, qualitative, or some combination of approaches during each phase of the research process. Depending on the approach used, researchers will conduct research differently. Quantitative research is a type of psychological research in which the researcher decides what to study; asks specific, narrow questions; collects numeric (numbered) data from participants; analyzes these numbers using statistics; and conducts the inquiry in an unbiased, objective manner. Qualitative research on the other hand, is a type of psychological research in which the researcher relies on the views of participants; asks broad, general questions; collects data consisting largely of words (or text) from participants; describes and analyzes these words for themes; and conducts the inquiry in a subjective, biased manner. 

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