This document discusses various research designs used in nursing research. It defines research design as the plan or blueprint for conducting a study. Experimental designs aim to identify cause-effect relationships through manipulation of independent variables and use of control groups. True experiments allow the highest level of control but quasi-experiments and pre-experimental designs are also used when true experiments are not possible. Non-experimental designs observe variables without manipulation and are used when variables cannot be manipulated or experiments would be unethical.

1. RESEARCH DESIGNS
Mrs. B.Gomathi,
Associate Professor and Head,
Dept of OBG Nsg,
SUM Nursing College,
SOA (DTU), BBSR.

2. Definition
 The research design is the plan, structure,
and strategy of investigations for answering
the research question .
 It is the overall plan or blue print the
researchers select to carry out their study.

3. Purpose of Research Design
 According to Kerlinger, The research
design has two purposes;
1. To provide answer to research
question
2. To control variance.

4. Elements of Research Design
A good research design includes several
elements:-
1. Description of subjects (who)
2. Observation of variable (what)
3. Measures of time (when)
4. Selection of setting(where)
5. Role of the investigator

5. EXPERIMENTAL DESIGNS

6. Control over the Independent
Variable
 True experimental
 Quasi experimental
 Pre-experimental

7. Experimental research designs
 Identifies cause-effect relationships
 Researchers are active agents, Not Passive
observers
 Answer questions about the effectiveness of
interventions.
 Gold standard for evidence based practice.

8. 1. TRUE EXPERIMENTAL
DESIGNS

9. Characteristics of true
experiments
 Manipulation: Experimenter does something to at
least some subjects
 Control: Experimenter introduces controls over the
experimental situation including use of a control
group
 Randomization: Experimenter assigns subjects to a
control or experimental group on a random basis

10. Basic experimental designs
 Pretest- posttest design (before-after design)
 Posttest only design (after-only design)
 Solomon four- group design
 Factorial design
 Randomized block design
 Crossover design (repeated measure design)

11. 1. Pretest- posttest design
(before-after design)
 Most commonly used
 Two randomized groups
 One group receives the experimental treatment
 Other group receiving no treatment, a placebo
treatment, or the usual treatment

12.  Comparison of the pretest scores allows
evaluation of the effectiveness of
randomization
 Treatment is under the control of the
researcher
 The dependent variable is measured twice,
before & after the manipulation of the
independent variable
 Comparison of the posttest scores allows
determining the effect of the independent
variable

13. Group Pretest Intervention Posttest
R C O1 O2
R E O1 X O2

14.  Impact of an adaptation training program
for patients with end stage renal disease.
Shiow, Yuh & Ching Lee (2005)
 57 patients randomly assigned to two
groups
 Intervention: Adaptation training program:
group sessions over 8 week period &
monthly follow up
 Control group received usual care
 Outcome measure: QOL, HD stressor scale,
depression inventory, medical outcomes at
0 & 3 months

15.  Effectiveness of accupressure in improving
dyspnea in COPD patients
 44 patients randomly assigned to two groups
 Intervention: True accupoint pressure, 5 sessions
per week & 16 minutes per session. 20 sessions
over 4 weeks period
 Control group: Routine treatment
 Outcome measure: Pulmonary function status,
dyspnea questionnaire, anxiety & 6 minute walk
test, at 0 & 4 wks

16. 2. Posttest only design
(after-only design)
Group Pretest Intervention Posttest
R C O
R E X O

17.  Effect of a new educational strategy on students’
attitudes towards patients
 Reduces the effect of pretest sensitization

18. 3. Solomon four group design
 Involves two experimental groups & two control
groups
 One experimental & one control group are
administered pretest & other groups are not
 Allows the effects of pretest measure &
intervention to be segregated

19. Group Pretest Intervention Posttest
C O1 O2
C O2
E O1 X O2
E X O2

20. 4. Factorial design
 Used to manipulate two or more independent
variables simultaneously
 Independent Variables - Factors
 Each factor – levels (two or more)
 Treatment condition – cell (Box)
 Designs - 2 x 2, 2 x 3, 3 x 3, 3 x 4

21. Factorial design (2X3)
Intervention A1 (Auditory) A2 (Tactile)
B1 (15mts) A1 B1 A2 B1
B2 (30mts) A1 B2 A2 B2
B3 (45mts) A1 B3 A2 B3

22. Factorial design (2X3)
Intervention for pain relief in cancer patients
Relaxation
A1
Music therapy
A2
Once daily
B1
A1 B1 A2 B1
Twice daily
B2
A1 B2 A2 B2
Thrice daily
B3
A1 B3 A2 B3

23. 5. Randomized Block Design
 Looks like factorial design in structure.
 Two factors (independent variables) but one
factor not experimentally manipulated e.g.
tactile verses auditory stimulation for male
verses female infants, structure 2x2
experiment.
 Type of stimulation one factor & gender as
the other.

24. ▪ Variable gender, cannot be manipulated, blocking
variable
▪ Male & female subjects are randomly assigned to
two stimulation methods.
▪ Inclusion of blocking variable enhances
researcher’s control over sample composition.
▪ Gender confounding variable, male & female
infants will respond differently to two therapies

25. Randomized block design (2x2)
Male
B1
Female
B2
Interventio
n -A1
Interventio
n - A2

26. 6. Crossover design
(Repeated measure or counterbalanced design)
 Involves exposure of same subjects to more than
one experimental treatment
 Subjects are randomly assigned to different
orderings of treatment
 Subjects serve as their own control
 Extremely powerful design but inappropriate for
certain types of research due to problem of
carry-over effects

27.  Effects of soy protein rich diet on renal
function in young adults with insulin
dependent DM. Stephenson et al (2005)
 12 Type I DM patients
 4 weeks assessment of baseline data
 Assigned to soy or control diet for 8
weeks
 Crossed over to alternative diet for 8
wks
 Outcome measures: GFR, LDL
cholesterol, urinary excretion of soy
isofavones at the end of each 8 wk
period

28. Experimental condition
(formal protocol)
 What is the intervention? How does it differ from
usual methods of care?
 If there are two alternative interventions, how
exactly do they differ?
 What are the specific procedures to be used with
those receiving the intervention?
 What is the dosage or intensity of the intervention

29.  Over how long a period will the intervention be
administered, how frequently it will be
administered, and when will the treatment
begin?
 Who will administer the intervention? What
are their credentials, and what type of special
training will they receive?
 Under what conditions will the intervention be
withdrawn or altered?

30. Control condition
 Control group condition used as a basis of comparison
in a study is referred to as the counterfactual
 An alternative intervention
 A placebo or psuedo intervention presumed to have no
therapeutic value
 Standard methods of care
 Different doses or intensities of treatment
 Delayed treatment

31.  Needs to be as carefully spelt out as the
intervention
 Explain what the condition was & how different it
was from the intervention being tested

32. Strength of experiments:-
▪ True experiments are most powerful
method.
▪ Yield the highest quality evidence
▪ Can predict, control, infer causal
relationships

33. Experimental limitations:-
• Criticized for their artificiality
• Focus on handful of variable- all other
constant
• Little control on research environments.
• Hawthorn effect, placebo effect.

34. QUASI AND PRE EXPERIMENTAL
DESIGNS

35. Quasi experiments
 Like true experiments, involve the manipulation of an
IV, i.e. an intervention
 However these designs lack randomization to
treatment groups
 Facilitate search for knowledge & examination of
causality in situations in which complete control is not
possible
 Developed to control as many threats to validity as
possible

36. 1. Non equivalent control group
pretest posttest design
Pretest Intervention Posttest
O1 X O2
O1 O2

37. Non equivalent control group
pretest posttest design
 Introduce QAM model in one hospital & study its impact on job
satisfaction of nurses
 Use job satisfaction of nurses in another similar hospital as
comparison
 If two groups are similar on pretest we could be relatively
confident that the difference in posttest is a result of the
intervention
 In quasi experiments the term comparison group is used in lieu of
control group

38. 2. Non equivalent control group posttest only
design
Intervention Posttest
X O
O

39. Non equivalent control group posttest only
design
 Suppose if we are unable to collect pretest data in the last
study our design will have a flaw which is difficult to
remedy
 We no longer have the information about the initial
equivalence of the two groups
 If we find the job satisfaction in the exp group lower we
would conclude that the introduction of the model caused
this.
 There could be an alternate explanation for the posttest
differences

40. 4.Time series design-
interrupted time series design
 Information is collected over an extended period & an
intervention is introduced during that period
 Maintaining consistency in record keeping etc can be a
problematic
 Can have problem of attrition
 Seasonal variations or other cyclical influences can be
interpreted as treatment effects
 Even small numbers of measurement points can provide
better information than cross sectional studies

41. Time series design-
interrupted time series design
O1 O2 O3 O4 X O5 O6 O7 O8

42.  Effect of foot massage on two phases of post
op CABG patients.
 On 2nd post op day after extubation
Pretest Posttest
O1 X O2 O3 O4 O5
 Outcome measure: HR, RR, BP, Pain Relaxation before
& at 0, 5, 10, 15 min

43.  Effect of a stimulation program on
development of LBW babies

44. 5. Time series non equivalent
control group design
O1 O2 O3 O4 X O5 O6 O7 O8
O1 O2 O3 O4 O5 O6 O7 O8

45. 6.Time series with multiple institutions
of treatment
O1 O2 X O3 O4 X O5 O6 X O7 O8

46. 7. Time series with intensified
treatment
O1 O2 X O3 O4 X+1 O5 O6 X+2 O7 O8

47. 8.Time series with withdrawn &
reinstituted treatment
O1 O2 X O3 O4 (-X) O5 O6 X O7 O8

48. Strengths of Quasi- experiments
 Practical
 Difficult to conduct true experiments in nursing
research in real life setting
 Several rival hypotheses competing with
intervention as explanation for the results
 Take the weaknesses into account in interpreting
results

49. Limitations of Quasi experiments
 Several rival hypotheses competing with
intervention as explanation for the results
 Take the weaknesses into account in
interpreting results

50. Internal validity
Extent to which it is possible to make an
inference that the IV is truly causing or
influencing the DV & that the relationship
between the two is not the spurious effect of an
extraneous variable

51. Threats to internal validity
 History
 Selection
 Maturation
 Testing
 Instrumentation
 Mortality

52. External validity
Generalizability of the research findings
to other settings or samples

53. Threats to external validity
 Expectancy effects
 Novelty effects
 Interaction of history & treatment effects
 Experimenter effects
 Measurement effects

54. 3. One group pretest posttest design
(pre experimental)
Pretest Intervention Posttest
O1 X O2

55.  More commonly used design and Has serious
weaknesses that findings are often uninterpretable
 Pretest scores cannot serve the same function as a
control group
 Events can occur between the pre & posttest that can
alter the response to posttest
 These events can serve as alternate hypotheses

56. NON EXPERIMENTAL
RESEARCH DESIGNS

57. NON-EXPERIMENTAL DESIGNS
It is a research design in which variables
are not deliberately manipulated, nor is the
setting controlled. Data in non experimental
research are generally collected through the use
of questionnaires, interviews, observations,
literature reviews and critical incident
technique.

58. Need of non experimental designs
Where……..
1. Independent variable cannot be manipulated.
2. Unethical to manipulate the independent
variables.
3. Not practically possible to conduct experiments.

59. Types of non experimental research designs
1. Descriptive designs
✓Univariant descriptive designs
✓Exploratory descriptive designs
✓Comparative descriptive designs
2.Correlational / Ex-post facto design
✓Prospective designs
✓Retrospective designs

60. 3. Developmental research designs
✓Cross sectional survey designs
✓Longitudinal survey designs
4. Epidemiological studies
✓Case control studies
✓Cohort studies
5. Survey research designs

61. 1.DESCRIPTIVE RESEARCH DESIGNS
The purpose of this study is to observe,
describe and document aspects of a situation as it
naturally occurs and sometimes to serve as a
starting point for hypothesis generation or theory
development.

62. a. Univariant descriptive designs
This designs are undertaken to describe the
frequency of occurrence of a phenomenon.
There are mainly two types of descriptive
studies in the field of epidemiology; incidence and
prevalence studies.
Eg…….
Prevalence of backache among antenatal
mothers admitted in antenatal ward.

63. b. Exploratory design
This design is used to identify, explore and
describe the existing phenomenon and its related
factors.
Eg………
An exploratory study on the contributing factors
of sleep disturbance among antenatal mothers attending
antenatal OPD.

64. C. Comparative designs
Comparative designs involves comparing and
contrasting two or more samples of the study
subjects on one or more variables, often at a single
point of time.
Eg………
A comparative study on health problems rural
and urban older people in dehradun district,
uttarakhand.

65. 2. CORRELATIONAL / EX-POST FACTO
RESEARCH DESIGN
This is a non experimental research designs,
where the researcher examines the relationship
between two or more variables in a natural setting
without manipulation or control.

66. a. Prospective research design
A design in which the researcher relates the
present to the future is a prospective research
design.
Eg…….
A prospective correlational study to assess the
relationship of maternal infection during pregnancy and
fetal development and pregnancy outcome.

67. b. Retrospective research designs
A design in which the researcher studies the
current phenomenon by seeking information from
past is a retrospective research design.
Eg………
A retrospective correlational study on the
lifestyle practices of the patients diagnosed with
coronary artery disease admitted in CCU, in Himalayan
hospital, Dehradun.

68. 3. DEVELOPMENTAL RESEARCH DESIGNS
Developmental research design examines the
phenomenon with reference to time. Developmental
research designs are generally used as adjunct
research designs with other research designs such
as cross sectional descriptive, longitudinal
correlational studies.

69. a. Cross sectional design
Cross sectional research design is one in
which researcher collects data at particular point
of time ( one period of data collection)
Eg………
A study to assess the awareness on swine
flu among people of an area.

70. b. Longitudinal designs
Longitudinal designs is used to collect the
data over an extended time period.
Eg……..
Perception of nursing students towards
profession from the beginning of nursing program to
its end.

71. 4. EPIDEMIOLOGICAL RESEARCH DESIGNS
Epidemiological studies are generally
conducted to investigate causes of different
diseases in either prospective approaches (cause to
effect) or retrospective approaches (effect to
cause).

72. a. Cohort studies
In this design, a longitudinal approach is used
to investigate the occurrence of a disease in
existing presumed causes.
Eg……
Researcher longitudinally observes the smokers for
development of lung cancer.

73. b. Case – control studies
In this design, causes of a disease are
investigated after the occurrence of a disease.
Eg……..
The researcher investigates the history of
smoking in patients diagnosed with lung cancer.

74. 5. SURVEY RESEARCH DESIGNS
A survey is a research design which is used to
collect information from different subjects within
a given population having same characteristics of
interest.
Eg
Sample survey
Population survey

75. Types of survey
1. A/to nature of phenomenon under the study
✓Descriptive
✓Exploratory
✓Comparative
✓Correlational
2. A/to methods of data collection
✓Written survey
✓Oral survey
✓Electronic survey

76. Advantages of non experimental designs
1. Most suitable for the nursing research
studies
2. Extremely useful to enhance our
understanding about the real world settings
around us.
3. There are many research situations in which
it is simply not practical to conduct true
experiment.

77. Disadvantages of non experimental designs
1. Results obtained and the relationship between
the dependent and independent variables can never
be absolutely clear.
2. Non experimental studies are conducted for
comparative purposes using non randomly selected
groups , which may not be homogeneous and may
affect the generalizability of the study results.

78. QUALITATIVE RESEARCH DESIGNS
Qualitative research dealing with
phenomena that are difficult or impossible to
quantify mathematically, such as beliefs,
meanings, attributes, and symbols; it may
involve content analysis. Qualitative research
approaches have somewhat short and less well
defined plans.

79. IMPORTANCE OF QUALITATIVE RESEARCH
✓ Study social and cultural phenomena,
✓ Inductive approach for delivering and expanding
knowledge.
✓ Useful for exploring facts and developing
concepts about an area of interest that has
received little research attention.

80. CHARACTERISTICS OF QUALITATIVE
RESEARCH
✓ Emerge as study advances
✓ Flexible and elastic
✓ Multiple strategies of data collection
(triangulation)
✓ Holistic
✓ Intense researcher's involvement
✓ Ongoing data analysis.

81. Phases of qualitative research designs
✓ Orientation and overview phase
✓ Focused exploration
✓ Confirmation and closure

82. TYPES OF DATA COLLECTION
✓ Interactive interview
✓ Written description by participants
✓ Observation

83. TYPES OF QUALITATIVE DESIGNS
✓ Phenomenological research
✓ Ethnographic research
✓ Grounded theory
✓ Historical research
✓ Case study
✓ Action research

84. 1. Phenomenological research
It describes the structure of experiences as
they present themselves to consciousness, without
recourse to theory, deduction or assumptions from
other disciplines.
Eg……….
A phenomenological study on lived
experiences of tsunami victims in selected villages
of Tamilnadu.

85. 2. Ethnographic research
Focuses on the sociology of meaning
through close field observation of socio cultural
phenomena.
Eg…………..
A ethnographic study on socio cultural beliefs of
the people about antenatal, natal and postnatal care of
women in selected tribal communities of Rajasthan.

86. 3. Grounded theory
The term grounded theory means
that the theory developed from the research
is ‘ grounded’ or has its roots in the data from
which it was derived.
Eg……………
A grounded theory research on the adaptation
levels of people with post injury permanent physical
disabilities at AIIMS, Newdelhi.

87. 4. Historical research design
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.
Eg……….
A historical research on development of
nursing in India.

88. 5. Case study
Attempts to focus on a phenomenon by
studying in depth a single case example. The
case can be an individual, an event, a group or
an institution.
Eg………
A case study on the availability and utilization of
the emergency services in civil hospital, Ludhiana.

89. 6. Action research
Action research is a form of applied
research that tries to empower people through a
process that constructs and uses knowledge. It
tries to find practical solutions to problems
existing in the framework of an organization.
Eg……….
An action research on the practicability of
western nursing practice protocols in public and
private Indian health care organizations.

90. References
 Polit D.F and Beck C.T, Nursing Research
Generating & Assessing evidence for Nursing
Practice 2015, Wolters Kluwer (India)
 Houser, Janet, Nursing Research Reading,
using & creating evidence 2008 by Jones &
Bartlett Publishers.

91. ▪ Hott J.B & Budin, W.C Notter’s essentials of
Nursing Research. Sixth edition. 1999 Springer
Publishing Company.
▪ Johnross @ C.W Com.net Way of approaching
research quantitative design.
▪ Wikipedia, the free encyclopedia (2009)
Quantitative Research.
▪ Sharma SK. Nursing Research and Statistics.3rd
Elsevier Publisher.

92. ▪ Neill James htm, Quantitative Research
designs 03 Aug 2003.
▪ Gall, M.D, et. Al Educational Research: An
Introduction Quantitative Research
Design (chapter 10-13, PP 287-431), 7th
editor 2003, white plains New York,
Longman.