This presentation explains samping and data collection that you need when you conduct a research. The presentation prepared based on Ary et al.

1. SAMPLING AND DATA
COLLECTION
BASED ON ARY_ET_AL

2. SAMPLING
 Sampling, or selection of participants or sites, is important in qualitative
research just as it is in quantitative research.
 Qualitative researchers are purposeful in selecting participants and settings.
They select purposive samples believed to be sufficient to provide
maximum insight and understanding of what they are studying.

3.  Several variations on purposive sampling are used in
qualitative research, as described in Miles and
Huberman (1994) and in Marshall and Rossman (2006).
These strategies can be combined or mixed within
studies as well to meet multiple needs or to provide
triangulation.

4. SAMPLING (CONT…)
1. Comprehensive sampling. In comprehensive sampling,
every unit is included in the sample. For example, a study
of physically disabled students in a high school would
include all such students in the school.
2. Critical case sampling. Critical case sampling involves
the selection of a single unit that provides a crucial test of
a theory or program.

5. 3. Maximum variation sampling. In maximum variation sampling, units are
included that maximize differences on specifi ed characteristics. For
example, a study of U.S. high school students might include students from
schools that differ in location, student characteristics, parental
involvement, and other factors.
4. Extreme, deviant, or unique case sampling. Extreme case sampling selects
units that are atypical, special, or unusual.

6. 5. Typical case sampling. Typical case sampling selects units that are
considered typical of the phenomenon to be studied. In a study of
an elementary school, you would select a school considered typical
rather than a very high achieving school or a very low achieving
school
6. Negative or discrepant case sampling. This method of sampling
selects units that are examples of exceptions to expectations. The
researcher would intentionally look for examples that appear not to
confirm the theory being developed.

7. 7. Homogeneous sampling. Homogeneous sampling
selects a subgroup that is considered homogeneous in
attitudes, experiences, and so on. This approach may be
used with focus group interviewing.
8. Snowball, chain, or network sampling. Snowball, chain,
or network sampling occurs when the initially selected
subjects suggest the names of others who would be
appropriate for the sample.

8. 9. Intensity sampling. Intensity sampling involves selecting
participants who exhibit different levels of the
phenomenon of interest to the researcher. The
researcher would select several cases at each of several
levels of variation of the phenomenon.
10. Stratified purposeful sampling. Stratified purposeful
sampling attempts to ensure that subgroups are
represented so that comparisons can be facilitated.

9. 11. Random purposeful sampling. When the potential purposeful
sample is too large (e.g., when resources are limited), the credibility
of the study can be enhanced by randomly selecting participants or
sites from the larger group.
12. Theoretical or theory-based sampling. In theoretical sampling,
the researcher begins by selecting a person or site that exemplifies
the theoretical construct and continues to select new cases that
reflect the developing theory to include as the research unfolds and
the theory emerges.

10. 13. Criterion sampling. In this type of sampling, the researcher sets
the criterion and includes all cases that meet that criterion.
14. Opportunistic sampling. Opportunistic sampling takes advantage
of new leads or unexpected opportunities.
15. Convenience sampling. Convenience sampling is choosing a
sample based on availability, time, location, or ease of access.
Convenience sampling is not recommended because it may
produce evidence that is not credible. Studies of your children or
your workplace are examples of convenience sampling.

11. DATA COLLECTION
 The most common data collection methods used in
qualitative research are (1) observation, (2) interviewing,
and (3) document or artifact analysis.

12. OBSERVATION
 Observation is a basic method for obtaining data in qualitative
research and is more than just “hanging out.”
 Qualitative observation usually takes place over a more extended
period of time than quantitative observation. Also, qualitative
observation is more likely to proceed without any prior hypotheses.
 Observation approaches can be very time-consuming or intrusive, and
the researcher may infer meanings that are not those of the
observed—a danger particularly present in cross-cultural studies.

13. OBSERVATION (CONT…)
 Choosing an Observation Site - Guided by the research question, the
qualitative investigator must select a site in which to observe.
 Determining Researcher Roles - Marshall and Rossman (2006) provide
advice to consider related to the researcher’s role in a study. First is
the amount of “participantness” or level of involvement of the
researcher in the setting. Second is the extent of “revealedness” or
how well the participants are informed about the study,. Third is
“intensiveness” or “extensiveness,” indicating the amount of time and
duration of time spent in the setting. Fourth is study focus, ranging
from the specific with well-developed research questions and data
identifi cation needs to

14. OBSERVATION (CONT…)
 Using Field Notes The most common method of recording the data collected during
observation is field notes. The researcher may make brief notes during the
observation but then later expands his or her account of the observation as field
notes. Notes may supplement information from other sources, including documents
and interviews, or they may comprise the main research data.
 The researcher’s field notes present the data that will later be analyzed to provide an
understanding of the research setting and the behavior of people within that setting.

15. INTERVIEWS
 The interview is one of the most widely used and basic methods for
obtaining qualitative data. Interviews are used to gather data from people
about opinions, beliefs, and feelings about situations in their own words.
 Interviews may provide information that cannot be obtained through
observation, or they can be used to verify observations.
 One of the most efficient ways to collect interview data is to use an audio
recorder. This is much less distracting than taking notes, and it also
provides a verbatim record of the responses.

16. INTERVIEW
 Interviewers need skill and practice to carry out a successful
interview: They must be tactful, well prepared (so that they
know what questions to ask), and listen well. Seidman (2006)
describes three levels of listening:
(1) listening to what the participant is saying;
(2) listening to the “inner voice,” the unguarded response that
is not targeted to an external audience;
(3) listening while remaining aware of process and nonverbal
cues.

17. STRUCTURE OF INTERVIEWS:
1. Unstructured interview.
2. Structured interview.
3. Semi- or partially structured interview.

18. DOCUMENTS AND ARTIFACTS
 The term documents here refers to a wide range of written, physical, and
visual materials, including what other authors may term artifacts.
Documents may be personal, such as autobiographies, diaries, and letters;
official, such as files, reports, memoranda, or minutes; or documents of
popular culture, such as books, films, and videos.
 Documents can be classified into four categories: (1) public records, (2)
personal documents, (3) physical materials, and (4) researcher-generated
documents.

19. DOCUMENTS AND ARTIFACTS (CONT..)
 If a document is written by someone who has had fi rsthand experience
with the phenomenon under study, it is considered a primary source. For
example, researchers have used diaries and letters written by pioneer
women to understand what life was like for such women in the early years
of our country.
 A secondary source is a secondhand description written by someone who
may have heard about an event from others but did not directly experience
it.

20. RIGOR IN QUALITATIVE RESEARCH
 Credibility
The integrity of qualitative research depends on attending
to the issue of validity. Validity concerns the accuracy or
truthfulness of the findings. The term most frequently
used by qualitative researchers to refer to this
characteristic is credibility.

21. RIGOR IN QUALITATIVE RESEARCH (CONT..)
 Transferability is the degree to which the findings of a qualitative
study can be applied or generalized to other contexts or to other
groups. In quantitative research, the term external validity is used to
refer to the generalizability of the findings.
 Transferability of a set of findings to another context depends on the
similarity or “goodness of fit” between the context of the study and
other contexts. The transfer is made by the potential user of the
findings, who must compare and decide on the similarity of the two
contexts.

22. RIGOR IN QUALITATIVE RESEARCH (CONT..)
 Dependability
Quantitative research, in which tight controls enhance
replicability, qualitative studies expect variability because the
context of studies changes. Thus, consistency is viewed as the
extent to which variation can be tracked or explained. This is
referred to as dependability or trustworthiness.

23. RIGOR IN QUALITATIVE RESEARCH (CONT..)
 Confirmability in qualitative research is the same as the
quantitative researcher’s concept of objectivity. Both deal with
the idea of neutrality or the extent to which the research is
free of bias in the procedures and the interpretation of results.