Quantitative Terms

Quantitative versus Qualitative Data

The two most common forms of research in the continuum of research methods are quantitative and qualitative.  While there are some similarities between the two, research generally tends to favor one approach over the other when examining issues such as research problems, potential audience, and personal experience (Creswell, 2012, p. 19-20).  In particular, a significant differentiating factor comes from the type of data being collected and how it is analyzed.

In quantitative research, a research problem is formed based on specific variable trends and the need to explain why something occurs (Creswell, 2012, p. 13).  Data is collected using an instrument, which uses specific questions to record data in the form of numbers (Creswell, 2012, p. 14).  The aspects of the data are then analyzed with mathematical procedures, known as statistics (Creswell, 2012, p.19).  In qualitative research, a research problem is formed based on a central phenomenon where specific variables may be unknown, so the answers are found by examining study participants (Creswell, 2012, p. 17).  Data is collected using protocols, which asks participants general and open-ended questions (Creswell, 2012, p. 17).  The aspects of the data, such as words or images, are then analyzed for overall descriptions or themes (Creswell, 2012, p. 19).

 

Focus Groups Pro’s and Con’s

Focus group interviews, or the collection of data through interviews with a small group of specific people, can be a very useful tool in both qualitative and quantitative research.   Unlike one-on-one interviews, focus groups can be extremely effective during constraints of time and money, particularly if the group is cooperative with each other (Creswell, 2012, p. 218).   Unlike telephone or email interviews, focus groups also have the advantage of being held in-person and can avoid certain limits in communication.   Overall, if conducted efficiently, focus groups allow the collection of extensive and valuable data (Krueger, 1994; in Creswell, 2012, p. 384).

However, there are also disadvantages to focus group interviews.  There is always the possibility of group members being uncooperative with either the interviewer or fellow group members.  If an interviewer lacks the control over the discussion, it is possible for individuals to take over the conversation and lead to an inaccurate group consensus (Creswell, 2012, p. 384).  It is also possible to have a group that is too large or too active to allow the researcher to take accurate notes or the transcriptionist to discriminate voices on audiotaped interviews (Creswell, 2012, p. 219).

 

Correlation is not necessarily Causation

To simplify, the two main variables in quantitative research can be identified as independent or dependent.  Researchers observe independent variables to see what effect they have on the outcome—or dependent variable— of the research (Creswell, 2012, p. 116).  However, researchers must be aware that the correlation they find between variables does not necessarily imply causation.   Sometimes there are unmeasurable, extra attributes—called confounding variables— that cannot be separated from other variables (Creswell, 2012, p. 119).  Confounding variables can influence the relationship between the independent and dependent variables, making them appear to be related (Creswell, 2012, p. 119).  Thus causation must be demonstrated.  Rather than prove a cause-and-effect relationship between independent and dependent variables, researchers use an idea known as “probable causation” to make possible suggestions as to how variables affect each other (Creswell, 2012, p. 120).

 

Ethnographic Research

            Ethnography means writing about groups of people and their culture, including their beliefs, behaviors, and language (Creswell, 2012, p. 461).  Ethnographic research uses qualitative procedures (or designs) to analyze and understand shared patterns within a culture (Creswell, 2012, p. 462).   These designs can have an incredibly narrow focus (i.e. on a particular group of people) or be broadly framed (i.e. an entire population), and can also range from day-to-day happenings to over a long period of time (Creswell, 2012, p. 462).  Regardless of who is being studied, researchers collect extensive amounts of data in the “field” through procedures such as interviews and observation, in order to create a detailed ethnographic description (Creswell, 2012, p. 470-72). Overall, the researcher should employ a “reflexive” approach to openly discuss their role in the ethnographic research that respects the research site and participants (Creswell, 2012, p. 474).

 

Case Studies

With a strong foundation in ethnography, a case study uses extensive data collection to analyze what John W. Creswell identifies as a “bounded system,” or a subject that has been disconnected from time and place for research (2012, p. 465).  Like ethnographic research, case studies consist of in-depth exploration of groups of people; however, case studies can also focus on activities, events, programs, processes, or even individuals (Stake, 1995; in Creswell, 2012, p. 465).  The three main types of qualitative case studies are intrinsic (where a case is studied because it is unusual or has merit), instrumental (where a case is studied that provides insight to an overlying issue), and collective (where several cases are studied that provide insight to an overlying issue) (Creswell, 2012, p. 466).

 

Student t-tests

If researchers make a hypothesis about an entire population, they need a simpler way to collect and analyze results than by testing every single person.  Luckily, researchers can test their hypothesis by analyzing data from the mean of a smaller sample by using a method of inferential statistics known as a student t-test (Creswell, 2012, p. 182).  When a population standard deviation is unknown, examining the mean of a small, normally distributed population is a more efficient way to assess a hypothesis about an entire population (Encyclopaedia Brittanica Online, 2014).

 

Participant Observation

Observation is one of the key, most frequently used methods of collecting qualitative data, especially in an educational setting (Creswell, 2012, p. 212).  By playing the role of observer, researchers are able to gather open-ended, firsthand information about people and places at a research site (Creswell, 2012, p. 213).  While it may be beneficial to start qualitative research as a nonparticipant observer, roles can be changed to a participant observer as the researcher adapts to the situation (Creswell, 2012, p. 215).  Participant observation occurs when the observer takes on an “inside” role and actively partakes in and records information about activities happening around them (Creswell, 2012, p. 214).

 

References

Encyclopaedia Britannica Online (2014, February 13). Student’s t-test. Retrieved from

http://www.britannica.com/EBchecked/topic/569907/Students-t-test

Creswell, J.W. (2012). Educational research: Planning, conducting, and evaluating quantitative

and qualitative research. Boston: Pearson.

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