WHAT IS METHODOLOGY? WHAT IS RESEARCH? WHAT IS RESEARCH METHODOLOGY? STUDY DESIGNS WHAT IS DESCRIPTIVE STUDY? WHAT IS ANALYTICAL STUDY? CONCLUSION REFERENCES The need for good research is to find the best evidence for clinical practice, for specific problems, and to address methods in reducing the burden of illness on a larger scale. It should reflect the aspirations and expectations of the research topic.

1. Dr. BEENA VIJAYAN PARVATHY
1st YEAR POST GRADUATE
Dept of Periodontics and Implantology
RESEARCH METHODOLOGY

2. 1. WHAT IS METHODOLOGY?
2. WHAT IS RESEARCH?
3. WHAT IS RESEARCH METHODOLOGY?
4. STUDY DESIGNS
5. WHAT IS DESCRIPTIVE STUDY?
6. WHAT IS ANALYTICAL STUDY?
7. CONCLUSION
8. REFERENCES
CONTENTS

3. WHAT IS METHODOLOGY?
Methodology is the systematic, theoretical analysis of the methods
applied to a field of study. It comprises the theoretical analysis of the
body of methods and principles associated with a branch of
knowledge.
(Irny and Rose, 2005) said that it encompasses concepts such as
paradigm, theoretical model, phases and quantitative or qualitative
techniques.

4. WHAT IS RESEARCH?
Research is a combination of both experience and reasoning and can
be said to be the most appropriate way of discovering the truth,
precisely in the natural sciences. It is a logical and systematic search
for new and useful information on a particular topic.
It is an investigation of finding solutions to scientific and social
problems through objective and systematic analysis. A research can
lead to new contributions to the existing knowledge.
Research has to be an active, diligent and systematic process of
inquiry in order to discover, interpret or revise facts, events,
behaviours and theories.

5. Qualities of Good Research (Igbokwe,2009)
A good research method should lead to:
i. Originality/ Novelty
ii. Contribution to knowledge
iii. Significance
iv. Technical soundness
v. Critical assessment of existing work

6. Research objectives falling into a number of following broad
groupings:
 Exploratory or Formulative Research studies: To gain familiarity
with a phenomenon or to achieve new insights into it.
 Descriptive Research studies : To depict accurately the
characteristics of a particular individual, situation or a group
 Diagnostic Research studies: To determine the frequency with
which something occurs or with which it is associated with something
else.
 Hypothesis-Testing Research studies: To test a hypothesis of a
causal relationship between variables.

7. Categories of Research
According to its Purpose
1. Basic/Theoretical Research
Also referred to as pure or fundamental, focuses on generating
knowledge, regardless of its practical application. It is usually
considered to involve a search for knowledge without a defined goal
of utility or specific purpose.
2. Applied Research
It is problem-oriented, and is directed towards the solution of an
existing problem.
According to Depth of Scope
1. Exploratory Research
It is used for the preliminary investigation of a subject that is not yet
well understood or sufficiently researched.

8. 2. Descriptive Research
It is to define the characteristics of a particular phenomenon without
necessarily investigating the causes that produce it.
3. Explanatory Research
It is responsible for establishing cause-and-effect relationships that allow
generalisations to be extended to similar realities.
4. Correlational Research
It is to identify the relationship between two or more variables. It aims to
determine whether a variable changes, how much the other elements of
the observed system change.

9. According to the Type of Data Used
1.Qualitative Research(Non-numeric)
It collects, compares and interpret information, has a linguistic-semiotic
basis and is used in techniques such as discourse analysis, interviews,
surveys, records and participant observations.
2. Quantitative Research(Numeric)
This study delves into a phenomena through quantitative data collection
and using mathematical, statistical and computer-aided tools to measure
them.
According to the Degree of Manipulation of Variables
1. Experimental Research
It is about designing or replicating a phenomenon whose variables are
manipulated under strictly controlled conditions in order to identify or
discover its effect on another independent variable or object.

10. 2. Non-Experimental Research
Also known as an observational study, the researcher does not intervene
directly, but limits their involvement to measuring the variables required
for the study.
3. Quasi-Experimental Research
It controls only some variables of the phenomenon under investigation
and is therefore not entirely experimental. The study and the focus group
cannot be randomly selected, but are chosen from existing groups or
populations.

11. According to the Type of Inference
1.Deductive Investigation
In this type, reality is explained by general laws that point to certain
conclusions; conclusions are expected to be part of the premise of the
research problem and considered correct if the premise is valid.
2. Inductive Research
In this type, knowledge is generated from an observation to achieve a
generalisation. It is based on the collection of specific data to develop
new theories.
3. Hypothetical-Deductive Investigation
It is based on observing reality to make a hypothesis, then use deduction
to obtain a conclusion and finally verify or reject it through experience.

12. According to the Time in Which it is Carried Out
1. Longitudinal Study (also referred to as Diachronic Research)
It is the monitoring of the same event, individual or group over a defined
period of time. It aims to track changes in a number of variables and see
how they evolve over time.
2. Cross-Sectional Study (also referred to as Synchronous Research)
It is used to observe phenomena, an individual or a group of research
subjects at a given time.
According to The Sources of Information
1. Primary Research
It is defined by the fact that the data is collected directly from the source,
that is, it consists of primary, first-hand information.

13. 2. Secondary research
It is developed with information from secondary sources, which are
generally based on scientific literature and other documents compiled by
another researcher.
According to How the Data is Obtained
1. Documentary (cabinet)
Also called secondary sources, is based on a systematic review of
existing sources of information on a particular subject. This type of
scientific research is commonly used when undertaking literature
reviews or producing a case study.

14. 2. Field
Study involves the direct collection of information at the location where
the observed phenomenon occurs.
3. From Laboratory
This research is carried out in a controlled environment in order to
isolate a dependent variable and establish its relationship with other
variables through scientific methods.
4. Mixed-Method: Documentary, Field and/or Laboratory
It combine results from both secondary (documentary) sources and
primary sources through field or laboratory research.

15. WHAT IS RESEARCH
METHODOLOGY?
Research methodology is a systematic way to solve a problem. It means
a guide to research and how it is conducted. Its aim is to give the work
plan of research.
Essentially, the procedures by which researchers go about their work of
describing, explaining and predicting phenomena are called Research
methodology.

16. Advantages Of Research Methodology:
The following are the advantages of research methodology:
1. Advancement of wealth of human being
2. Provision of tools for carrying out the research
3. Develops a critical and scientific attitude, disciplined thinking to
observations
4. Enrichment of the research process and provision of chance for in
depth study and understanding of the subject
5. Helps to inculcate the ability to evaluate and use research results
with reasonable confidence and in decision making
6. Inculcates the ability to learn to read and think critically.

17. STUDY DESIGNS
Research study design is a framework, or the set of methods and
procedures used to collect and analyze data on variables specified in a
particular research problem.
The type of study design used to answer a particular research question is
determined by:
the nature of question
 the goal of research
 the availability of resources

18. There are some terms that are used frequently while classifying study
designs:
Variable
It represents a measurable attribute that varies across study units. It can
be individual participants in a study, or at times even when measured in
an individual person over time. Some examples of variables include age,
sex, weight, height, health status, alive/dead, diseased/healthy, annual
income, smoking yes/no, and treated/untreated.
Exposure (or intervention) and outcome variables
A large proportion of research studies assess the relationship between
two variables. Exposure (or intervention) refers to the risk factor whose
effect is being studied. It is also referred to as the independent or the
predictor variable.

19. The outcome (predicted or dependent) variable develops as a
consequence of the exposure (intervention). The term “exposure” is used
when the “causative” variable is naturally determined (observational
studies – examples include age, sex, smoking, and educational status),
and the term “intervention” is preferred where the researcher assigns
some or all participants to receive a particular treatment for the purpose
of the study (experimental studies – e.g., administration of a drug).
Observational versus interventional (or experimental) studies
Observational studies are those where the researcher is documenting a
naturally occurring relationship between the exposure and the outcome
that he/she is studying. Observational studies can be either descriptive
(nonanalytical) or analytical (inferential).

20. Interventional studies are experiments where the researcher actively
performs an intervention in some or all members of a group of
participants.
Descriptive V/S Analytical studies
Descriptive (or nonanalytical) studies merely try to describe the data on
one or more characteristics of a group of individuals. These do not try to
answer questions or establish relationships between variables.
Analytical studies attempt to test a hypothesis and establish causal
relationships between variables. The researcher assesses the effect of an
exposure (or intervention) on an outcome. Analytical studies can be
observational (if the exposure is naturally determined) or interventional
(if the researcher actively administers the intervention).

23. Directionality of study designs
Based on the direction of inquiry, study designs may be classified as
forward-direction or backward-direction.
In forward-direction studies, the researcher starts with determining the
exposure to a risk factor and then assesses whether the outcome occurs at
a future time point. This design is known as a “cohort study”.
In backward-direction studies, the researcher begins by determining
whether the outcome is present (cases vs. noncases [also called controls])
and then traces the presence of prior exposure to a risk factor. These are
known as “case–control studies”.

24. Prospective V/S Retrospective study designs
The terms “prospective” and “retrospective” refer to the timing of the
research in relation to the development of the outcome.
In retrospective studies, the outcome of interest has already occurred in
each individual by the time she/he is enrolled, and the data are collected
either from records or by asking participants to recall exposures.
In prospective studies, the outcome has not occurred when the study
starts and participants are followed up over a period of time to
determine the occurrence of outcomes.
Most cohort studies are prospective studies whereas case–control studies
are retrospective studies.

25. WHAT IS A DESCRIPTIVE STUDY?
A descriptive study is one that is designed to describe the distribution of
one or more variables, without regard to any causal or other hypothesis.
Types Of Descriptive Studies
Descriptive studies can be of several types, namely, case reports, case
series, cross-sectional studies, and ecological studies. In the first three of
these, data are collected on individuals, whereas the last one uses
aggregated data for groups.
Case reports and case series
A case report refers to the description of a patient with an unusual
disease or with simultaneous occurrence of more than one condition. A
case series is similar, except that it is an aggregation of multiple (often
only a few) similar cases.

26. Cross-sectional studies
Cross-sectional study design involve the collection of information on the
presence or level of one or more variables of interest, whether exposure
or outcome, as they exist in a defined population at one particular time.
If these data are analyzed only to determine the distribution of one or
more variables, these are “descriptive”.
Cross-sectional studies are usually simple to do and inexpensive. Further
more, these usually do not pose much of a challenge from an ethics view
point.
This design does carry a risk of bias, if arises either selection bias or
measurement bias.

27. Ecological studies
Ecological (also sometimes called as correlational) study design involves
looking for association between an exposure and an outcome across
populations rather than in individuals.
The ecological study design has some limitations.
 An association between exposure and outcome at the group level may
not be true at the individual level (a phenomenon also referred to as
“ecological fallacy”).
The association may be related to a third factor which in turn is related
to both the exposure and the outcome, the so-called “confounding”.
 Migration of people between regions with different exposure levels
may also introduce an error.
The use of differing definitions for exposure, outcome or both in
different populations.

28. Advantages of Descriptive Studies
Very easy to conduct
Inexpensive
Quick
No need of too much effort.
Do not face serious ethics scrutiny
Useful for estimating the burden of disease
Disadvantages Of Descriptive Studies
Have pitfalls
The results can be unlikely to be reliable

29. WHAT IS analytical STUDY?
In analytical observational studies, researchers try to establish an
association between exposure(s) and outcome(s). Depending on the
direction of enquiry, these studies can be directed forwards (cohort
studies) or backwards (case–control studies).
In observational analytical studies, the exposure is naturally
determined as opposed to experimental studies where an investigator
assigns each subject to receive or not receive a particular exposure.

31. Cohort Studies
•A cohort is defined as a “group of people with a shared characteristics”.
•They have different groups of people with varying levels of exposure are
followed over time to evaluate the occurrence of an outcome.
•These participants have to be free of the outcome at baseline.
•The presence or absence of the risk factor (exposure) in each subject is
recorded.
•Subjects are then followed up over time (longitudinally) to determine the
occurrence of the outcome.
Thus, cohort studies are forward-direction studies (moving from exposure
to outcome) and are typically prospective studies (the outcome has not
occurred at the start of the study)

32. Advantages Of Cohort Studies
It is certain that the exposure preceded the outcome, and temporality
can be established.
For a given exposure, more than one outcome can be studied.
 Several exposures can be studied simultaneously.
Limitations Of Cohort Studies
Require a long duration of follow-up to determine whether outcome
will occur or not. Losses to follow-up, and logistic and cost issues pose
major challenges.
It is not uncommon for one or more unknown confounding factors to
affect the occurrence of outcome.

33. Uses Of Cohort Studies
Lack of random assignment to exposure, it is considered as having a
greater validity compared to the other observational study designs.
Can determine the risk of outcome among exposed persons and
unexposed persons.
When experimental studies are not feasible, cohort studies are a
reasonable and arguably the best alternative.
Cross-Sectional Studies
The collection of information on the presence or level of one or more
variables of interest whether exposure or outcome as they exist in a
defined population at one particular time. The investigator assesses the
relationship between the presence of an exposure and that of an outcome.

34. Case-Control Studies
•The researcher first enrolls cases (participants with the outcome) and
controls (participants without the outcome) and then tries to elicit a
history of exposure in each group.
•These are backward-direction studies and retrospective.
•Identification of appropriate controls is a key element of the case-
control study design and can influence the estimate of association
between exposure and outcome (selection bias).
•Controls are individually matched with cases for factors which are
considered important to the development of the outcome.
• To minimize assessment bias, it is important that the person assessing
the history of exposure is unaware of (blinded to) whether the participant
being interviewed is a case or a control.

35. Advantages Of Case–Control Studies
Cheap
Less time-consuming
Once cases and controls are identified and enrolled, it is often easy to
study the relationship of outcome with not one but several exposures.
Limitations Of Case–Control Studies
Temporality (whether the outcome or exposure occurred first) is often
difficult to establish.
There may be a bias in selecting cases or controls.
Confounding factors could influence.
The determination of exposure relies on existing records or history
taking (misinformation bias). Either can be problematic.

36.  It is backward-directed, there is no “at risk” group at the start
of the study; therefore, the determination of “risk” is not possible,
and one can only estimate “odds”.
Uses Of Case–Control Studies
Ideal for rare diseases, where identifying cases is easier than following
up large numbers of exposed persons to determine outcome.
Because of their simplicity and need for fewer resources, are often the
initial study design used to assess the relationship of a particular exposure
and an outcome

37. WHAT IS INTERVENTIONAL STUDY?
The researcher actively interferes with nature by performing an
intervention in some or all study participants to determine the effect of
exposure to the intervention on the natural course of events.
It can be divided broadly into two main types:
(i)“controlled clinical trials” (or simply “clinical trials” or “trials”), in
which individuals are assigned to one of two or more competing
interventions
(ii) “community trials” (or field trials), in which entire groups

38. Randomized Controlled Trials
•A group of participants fulfilling certain inclusion and exclusion criteria
is “randomly” assigned to two separate groups, each receiving a different
intervention. Random assignment implies that each participant has an
equal chance of being allocated to the two groups.
•The term “controlled” refers to the presence of a concurrent control or
comparator group. These studies have two or more groups – treatment
and control.
•The control group receives no intervention or another intervention that
resembles the test intervention in some ways but lacks its activity or
another active treatment.
•The outcomes are then compared between the intervention and the
comparator groups.

39. Nonrandomized Controlled Clinical Trials
•Participants are assigned to different intervention arms without
following a “random” procedure.
•This may be based on the investigator's convenience or whether the
participant can afford a particular drug or not.
•Although such a design can suggest a possible relationship between
the intervention and the outcome, it is susceptible to bias with patients in
the two groups being potentially dissimilar and hence validity of the
results obtained is low.

40. CONCLUSION
The need for good research is to find the best evidence for clinical
practice, for specific problems, and to address methods in reducing the
burden of illness on a larger scale.
It should reflect the aspirations and expectations of the research topic.

41. REFERENCES
1. Essentials Of Public Health Dentistry ( Community Dentistry)
By Soben Peter.
2. Jogikalmat Krithikadatta. Research methodology in Dentistry: Part 1
The essentials and relevance of research. Journal of Conservative
Dentistry ;Jan-Mar 2012;Vol 15;Issue 1.
3. Priya Ranganathan,Rakesh Aggarwal. Study designs: Part 1,2,3 and
4.Perspect Clin Res. 2018 Oct-Dec.