This document discusses various types of research designs and sampling methods used in nursing research. It describes the purposes of research as identification, description, exploration, explanation, prediction, and control. The main types of research designs are classified based on purpose, process, and outcome as exploratory, descriptive, analytical, predictive, quantitative, qualitative, applied, basic/pure, and action research. Probability and non-probability sampling methods are also outlined.

1. NURSING RESEARCH
Dr. Meena Ganapathy

2. Purposes of research
 Identification : what is the
phenomena?
 Description: What dimensions,
importance?
 Exploration: nature, trend, process
 Explanation: How, why, how did?
 Prediction: what will happen?
 Control: Can it be?, How to?

3. Research
Designs

4. Research Design
• Definition: Blueprint or
detailed plan for
conducting a study.

5. Design Characteristics
• Maximizes control over factors to
increase validity of the findings.
• Guides the researcher in planning
& implementing a study.

6.  Approach : According to Oxford
dictionary is a path that leads to a
place.
 Design : A general arrangements of
parts to make a whole.

7.  Types of research designs
 The main different types of research
designs can be classified by its
purpose, its process and its outcome.

8. Types based on purpose
 Explorative
 Descriptive
 Analytical
 Predictive

9. Types based on process
 Quantitative
 Qualitative

10. Types based on outcome
 Applied
 Basic / Pure
 Action

11. Quantitative
 It is categorized with descriptive research,
Correlational research, causal-comparative
research and experimental research
 It collects numerical data in order to explain,
predict and or control phenomena of interest;
 Data analysis is mainly statistical.

12. Qualitative
 It includes historical research and qualitative
research;
 It collects narrative data to gain insights into
phenomena of interest;
 Data analysis includes the coding of the data
and production of a verbal synthesis.

13. Descriptive
 Descriptive: it involves collecting
data in order to test hypotheses or
answer questions concerning the
current status of the subjects of the
study.
 It determines and reports the way
things are.

14. Correlational
 Correlational research attempts to
determine whether and to what degree a
relationship exists between two or more
quantifiable variables.
 However, it never establishes a cause-effect
relationship.
 The relationship is expressed by correlation
coefficient, which is a number between .00
and 1.00

15. Cause-comparative
 Causal-comparative research:
establishes the cause-effect
relationship, compares the
relationship, but the cause is not
manipulated, such as "gender."

16. Experimental
 Experimental research establishes the
cause-effect relationship and does the
comparison, but the cause is
manipulated.
 The cause, independent variable
makes the difference. The effect,
dependent variable is dependent on
the independent variable.

17. Criteria for experimental
designs
 Control
 Manipulation
 Randomization

18. Main Types of Qualitative
Research
 Case study
 Attempts to shed light on a
phenomena by studying in depth a
single case example of the
phenomena. The case can be an
individual person, an event, a group,
or an institution.

19. Grounded theory
 Theory is developed inductively from a
corpus of data acquired by a
participant-observer.
 It is used to formulate, test & refine a
theory about a particular phenomena.
Eg., grieving phenomena

20. Phenomenology
 Phenomenology
 Describes the structures of experience
as they present themselves to
consciousness, without recourse to
theory, deduction, or assumptions
from other disciplines. Eg., chronic
pain.

21. Ethnography
 Focuses on the sociology of meaning
through close field observation of
socio cultural phenomena. Typically,
the ethnographer focuses on a
community. Mainly done by
anthropologists to investigate culture

22. Historical
 Historical
 Systematic collection and objective
evaluation of data related to past
occurrences in order to test
hypotheses concerning causes, effects,
or trends of these events that may
help to explain present events and
anticipate future events. (Gay, 1996)

23. Assumptions
Dr. Meena Ganapathy

24. Assumptions
 Assumptions: Ideas that are
universally accepted as true. They can
also come from theory & previous
research. Sometimes they may not be
scientifically tested. But based on
logic.
 Eg., Life is stressful.
 Health is a priority for most people.

25. Hypothesis
Dr.Meena Ganapathy

26. Hypothesis
 A hypothesis is a statement that
expresses the probable relationship
between variables.
 There are two types of hypotheses:
descriptive and directional.
 The research question used in descriptive
studies is called Descriptive Hypothesis.
 Descriptive hypotheses ask a specific
question regarding some phenomenon.

27.  For example, we might want to study this
research question: what are the social and
economic characteristics of patients who
have high blood pressure?
 A descriptive hypotheses that would test a
part of the above research question is: what
is the distribution of hypertensive patients
by income level?

28.  Descriptive hypotheses are always phrased
in the form of a question regarding some
aspect of the research question.
 Usually a descriptive hypothesis does not
include an active independent variable.
When we use an independent variable, a
directional hypothesis is usually needed.

29. Directional hypotheses
 Directional hypotheses are never
phrased as a question, but always as a
statement.
 Directional hypotheses always express
the effect of an independent on a
dependent variable.

30. Examples
 Descriptive hypothesis : Does having social
support decrease depression in breast
cancer patients?
 Directional Hypothesis: Breast cancer
patients with social support will be less
depressed than those without social
support.
 Null /Ho : There is no difference in
depression scores between breast cancer
patients with and without social support

31. Types of directional
hypotheses
 Simple hypotheses
 One IV & one DV
 Complex hypotheses
 2 or more IVs & 2 or more DVs

32. Uses of Hypothesis
 They serve as a link between theory
and real world situations.
 They provide an effective mechanism
for extending knowledge.
 They offer overall direction for the
investigation.

33. Sampling
Dr.Meena Ganapathy

34.  What is a sample?
 A sample is a finite part of a statistical
population whose properties are
studied to gain information about the
whole (Webster, 1985).

35.  What is a population?
 A population is a group of individuals’
persons, objects, or items from which
samples are taken for measurement
for example a population of presidents
or professors, books or students.

36. Types of population
 Target population : is the set of individuals
or objects for which the researcher wishes
to generalize findings.
 The accessible population: is the portion of
the target population that is available to
researcher.
 Sample: it is the subset of population drawn
from the accessible population.

37. Purposes of sampling
 To draw conclusions by directly observing
only a portion (or sample) of the population.
 It is cheaper to observe a part rather than
the whole
 Taking a sample requires fewer resources
than a census
 A sample may provide you with needed
information quickly

39. Sampling Methods
 Probability sampling: samples drawn in
random manner so that every member
has an equal chance of being selected.
 Non probability sampling: samples
drawn in a non random manner.

40. Methods of probability
sampling
 Random sampling
 Stratified random
 Cluster
 Systematic

41. A simple random sample
 A simple random sample is obtained
by choosing elementary units in such a
way that each unit in the population
has an equal chance of being selected.
 A simple random sample is free from
sampling bias.

42. A systematic random sample
 A systematic random sample is
obtained by selecting one unit on a
random basis and choosing additional
elementary units at evenly spaced
intervals until the desired number of
units is obtained.

44. A stratified sample
 A stratified sample is obtained by
independently selecting a separate
simple random sample from each
population stratum.
 A population can be divided into
different groups may be based on
some characteristic or variable like
income or education.

46. A cluster sample
 A cluster sample is obtained by
selecting clusters from the population
on the basis of simple random
sampling.
 The sample comprises a census of
each random cluster selected.
 For example, a cluster may be some
thing like a village or a school, a state.

47. Methods of non probability
sampling
 Convenience sampling
 Quota
 Purposive
 Snow ball

48. Convenience sampling
 It is useful in getting general ideas
about the phenomenon of interest.
 For example you decide you will
interview the first ten people you meet
tomorrow morning.
 It saves time, money and effort.
 has the lowest credibility and yields
information-poor cases.

49. Quota Sampling
 In quota sampling, you select people
non randomly according to some fixed
quota.
 There are two types of quota
sampling: proportional and non
proportional

50. Purposive Sampling
 In purposive sampling, we sample with a
purpose in mind.
 We usually would have one or more specific
predefined groups we are seeking.
 For instance, have you ever run into people
in a mall or on the street who are carrying a
clipboard and who are stopping various
people and asking if they could interview
them?

51. Snowball or chain sampling
 This particular one identifies, who
know interview subjects.
 This is commonly used in studies that
may be looking at issues like the
homeless households.
 What you do is to get hold of one and
he/she will tell you where the others
are or can be found.