Quantitative Research Methods

1. Basic Qualitative Research Designs
Research design is a plan for collecting and analyzing evidence that will
make it possible for the investigator to answer whatever questions he
or she has posed.
The process of qualitative research may be described as a sequence of
decisions.
When you start your research and to propel your project, you can make a
choice
between a number of alternatives at various points in the process—from
questions
to data collection and analysis and ultimately to presentation of results. In
these decisions, you will set up the design of your study in a dual sense

2. Case Studies
The aim of case studies is the precise description or reconstruction of a
case. The term "case" is rather broadly understood here. You can take
persons, social communities (e.g., families), organizations, and
institutions (e.g., a nursing home) as the subject of a case analysis. Your
main problem then will be to identify a case that would be significant
for your research question and to clarify what else belongs to the case
and what methodological approaches its reconstruction requires.

3. Case Studies
If your case study is concerned with the school problems of a child, you
have to clarify, for instance, whether it is enough to observe the child in
the school environment. Or do you need to interview the teachers and/
or fellow pupils? To what extent should the family and their everyday
life be observed as part of the analysis?

4. Comparative Studies
In a comparative study, you will not observe the case as a whole and in
its complexity, but rather a multiplicity of cases with regard to
particular excerpts.
To be able to show cultural differences in the views of health among
Portuguese and German women, we selected interview partners from
both cultures. They had to lead similar lives in as many respects as
possible (big-city life, comparable professions, income, and level of
education) under at least very similar conditions in order to be able to
relate differences to the comparative dimension of "culture"

5. Retrospective Studies
Retrospective study: In medicine, a study that looks backward in time, usually
using medical records and interviews with patients who already known to have a
disease.
A study that compares two groups of people: those with the disease or condition
under study (cases) and a very similar group of people who do not have the disease or
condition (controls).
For example, if an investigator wanted to determine whether exposure to chemicals used
in tire manufacturing was associated with an increased risk of death, one might find a tire
manufacturing factory that had been in operation for several decades. One could
potentially use employee health records to identify those who had had jobs which involved
exposure to the chemicals in question (e.g., workers who actually manufactured tires) and
non-exposed coworkers (e.g., clerical workers or sales personnel in the same company or,
even better, workers also involved in manufacturing operations but with jobs that didn't
involve exposure to the chemicals). One could then ascertain what had happened to all the
subjects and compare the incidence of death in the exposed and non-exposed workers.

6. Longitudinal Studies
The final variant of a basic design in qualitative research consists of
longitudinal studies, in which an interesting process or state is analyzed
again at later times of data collection. This strategy has rarely been
used, at least explicitly, in qualitative research. In most qualitative
methods, you will find little guidance on how they could be applied in
longitudinal studies with several periods of data collection. Implicitly a
longitudinal perspective within a temporally limited framework is
realized in ethnography by virtue of the researchers' extended
participation in the field of study, and also—with a retrospective
focus—in biographical research, which considers an extended section
of a life history.

7. Combined, longitudinal qualitative research endeavors to understand
how people successively make meaning about the trajectories of their
lives, or specific conditions of their lives, by following them through
time. ... It is also a key to understanding how people experience and
respond to developmental change.
The great strength of a longitudinal study—being able to document
changes of view or action through repeated collection cycles, where
the initial state of a process of change can be recorded without any
influencefrom its final state—cannot therefore be fully realized.

8. Appropriateness of the
Method to the Issue
For the construction of a research design we should keep in mind that
there is no "ideal way" which fits every study. Research questions and
issues under study should define how sampling is planned and what
basic design should be selected. Theoretical sampling may be the most
ambitious way to select cases in qualitative research. Nevertheless it is
not the best choice in every study. Not all basic designs are appropriate
and easy to apply in every study in the same way.

9. Fitting the Approach into the Research
Process
This point of reference concerns selecting a sampling alternative or a
research design and fitting it into the research process. For planning a
study, collecting data, and analyzing them, the soundness of the
modules of the research should be checked. Is the flexibility in
collecting the data or the case orientation in analyzing them
compatible with the aims of a systematic comparison? Is the method
for collecting data open and comprehensive enough for doing a
complex case study with the data?

10. Checklist for Selecting a Research Design and Evaluating its
Application
1 Research question
Can the design and its application address the essential aspects of the research
question?
2 Design
The design must be applied according to the methodological elements and targets
There should be no jumping between research designs, except when it is grounded
in
the research question or theoretically
3 Researcher
Are the researchers able to apply the design?
What are the consequences of their own experiences and limits, resources, etc., in
the realization?

11. Checklist for Selecting a Research Design and Evaluating its
Application
4 Participant «
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af nthde e axpppelcictaattiioonn?s of (potential)
participants?
5 Scope allowed to the interviewee
Can the participants present their views in the framework of the questions?
Is there enough scope for the new, unexpected, and surprising?
6 Interaction with the field
Have the researchers applied the research design correctly?
Have they left enough scope for the participants?
Did they fulfill their role? (Why not?)
Were the participant's role, the researcher's role, and the situation clearly defined for
the participant?
Could the participants fulfill their roles? (Why not?)

12. Checklist for Selecting a Research Design and Evaluating its
Application
7 Aim of the interpretation
Are you interested in finding and analyzing limited and clear answers or
complex,
multifold patterns, contexts, etc.?
8 Claim for generalization
The level on which statements should be made:
• For the single case (the interviewed individual and his or her biography, an
institution and its
impact, etc.)?
• With reference to groups (about a profession, a type of institution, etc.)?
• General statements?

13. Purposive sampling
• Purposive sampling (also known as judgment, selective or subjective
sampling) is a sampling technique in which researcher relies on his or
her own judgment when choosing members of population to
participate in the study.
• Purposive sampling is a non-probability sampling method and it
occurs when “elements selected for the sample are chosen by the
judgment of the researcher. Researchers often believe that they can
obtain a representative sample by using a sound judgment, which will
result in saving time and money”

14. • TV reporters stopping certain individuals on the street in order to ask their
opinions about certain political changes constitutes the most popular
example of this sampling method. However, it is important to specify that
the TV reporter has to apply certain judgment when deciding who to stop
on the street to ask questions; otherwise it would be the case of random
sampling technique.
• Alternatively, purposive sampling method may prove to be effective when
only limited numbers of people can serve as primary data sources due to
the nature of research design and aims and objectives. For example, for a
research analysing affects of personal tragedy such as family bereavement
on performance of senior level managers the researcher may use his/her
own judgment in order to choose senior level managers who could
particulate in in-depth interviews.

15. Application of Purposive Sampling (Judgment
Sampling): an Example
• Suppose, your dissertation topic has been approved as the following:
• A study into the impact of tax scandal on the brand image of Starbucks
Coffee in the UK
• If you decide to apply questionnaire primary data collection method with
use of purposive sampling, you can go out to Oxford Street and stop what
seems like a reasonable cross-section of people in the street to survey.
• Another example. Your research objective is to determine the patterns of
use of social media by global IT consulting companies based in the US.
Rather than applying random sampling and choosing subjects who may not
be available, you can use purposive sampling to choose IT companies
whose availability and attitude are compatible with the study.

16. Advantages of Purposive Sampling (Judgment
Sampling)
1.Purposive sampling is one of the most cost-effective and time-
effective sampling methods available
2.Purposive sampling may be the only appropriate method available if
there are only limited number of primary data sources who can
contribute to the study
3.This sampling technique can be effective in exploring anthropological
situations where the discovery of meaning can benefit from an
intuitive approach

17. Disadvantages of Purposive Sampling
(Judgment Sampling)
1.Vulnerability to errors in judgment by researcher
2.Low level of reliability and high levels of bias.
3.Inability to generalize research findings

18. Width or Depth as Aims of Sampling
What is decisive when you choose one of the sampling strategies just
outlined, and for your success in putting together the sample as a
whole, is whether it is rich in relevant information. Sampling decisions
always fluctuate between the aims of covering as wide a field as
possible and of doing analyses which are as deep as possible. The
former strategy seeks to represent the field in its diversity by using as
many different cases as possible in order to be able to present evidence
on the distribution of ways of seeing or experiencing certain things. The
latter strategy seeks to further permeate the field and its structure
by concentrating on single examples or certain sectors of the field.

19. Considering limited resources (people, money, time, etc.) you should
see these aims as alternatives rather than projects to combine. In the
example mentioned above, the decision to deal more intensively with
one type of institution (socio-psychiatric services) and, due to limited
resources, not to collect or analyze any further data in the other
institutions, was the result of weighing width (to study trust in
counseling in as many different forms of institutions) against depth (to
proceed with the analyses in one type of institution as far as possible).