This document discusses research design and measurement. It defines research design and describes exploratory, descriptive, and experimental designs. Exploratory research is used to better understand undefined problems, descriptive research accurately describes variables, and experimental research tests hypotheses about causal relationships. Informal designs like before-after and after-only designs are less sophisticated, while formal designs like completely randomized and randomized block designs offer more control using statistics. Key concepts are also defined, like independent and dependent variables, and principles of experimental design like replication and randomization are explained.

1. UNIT-II
RESEARCH DESIGN AND
MEASUREMENT

2. Research design – Definition – types of research design –
exploratory and causal research design– Descriptive and
experimental design – different types of experimental design –
Validity of findings – internal and external validity – Variables in
Research – Measurement and scaling – Different scales –
Construction of instrument – Validity and Reliability of instrument.

3. RESEARCH DESIGN
MEANING: The framework developed to control the
collection of data is called research design.
DEFINITION: “A Research design is the arrangement of
condition for collection and analysis of data in a manner that
aims to combine relevance to the research purpose with
economic in procedure”.
“It is a blue print for the collection, measurement and
analysis of data”.

4. NEEDS FOR RESEARCH DESIGN
• Research design is needed because it gives the smooth going
of the various research operations, so making research as
efficient as possible we can get maximal information with
minimal expenditure of effort, time and money.
• It stands for advance planning of the methods to be used for
collecting the relevant data.

5. Features of a good design
A good design is flexible, appropriate, efficient, economical.
It should minimizes bias and maximizes the reliability of the
data.
It should yields maximal information.
It is related to the purpose or objective of the research problem.

6. Important Concepts Related To Research
Design
Dependent and independent variables: If one variable
depends upon another variable, it is termed as a dependent
variable.
The variable that is forerunner to the dependent variable
is termed is an independent variable.
Example: height depends upon age, then height is a dependent
variable, age is an independent variable.

7. Continuous and non continuous variable
• Different quantitative values is called a variables.
• A variable is a quantity that can be changed and is not fixed
Ex: weight, height, income.
The values mentioned in decimal points are called “continuous
variables”.
If they can only be expressed in integer, they are non continuous
variables/discrete variables.
Age is an example of continuous variables, but the number of
children is an example of non continuous variables.

8. Extraneous variable:
Independent variables that are related to the purpose of the
study but may affect the dependent variable are termed as
extraneous variable..
Control:
The technical term ‘control’ is used when we design the
study minimizing the effects of extraneous independent variables.
Experimental and control groups:
In an experimental hypothesis testing research when a group
is exposed to usual conditions, it is termed a ‘control group.’ but
when the group is exposed to some normal or special condition, it
is termed an ‘experimental group’.

9. DIFFERENT RESEARCH DESIGN

10. 1.Research Design In Case Of Exploratory Research
Studies
2.Research Design In Case Of Descriptive And
Diagnostic Research Studies.
3.Research Design In Case Of Hypothesis-testing
Research Studies

11. Research Design In Case Of Exploratory
Research Studies
The main purpose of the design is to
1)Identify the problems or opportunities.
2) Defining the problem more precisely.
3)Gaining deeper insight into the variables
operating in a situation.

12. Research Design In Case Of Descriptive And
Diagnostic Research Studies
• Descriptive research studies are those studies which
are concerned with describing the characteristics of a
particular individual or of a group.
• Diagnostic research studies to determine the analyze
of the frequency with which something occurs or its
association with something else.

13. Research Design In Case Of Hypothesis-testing
Research Studies
• Hypothesis-testing research studies(generally known
as experimental studies) are those where the researcher
test the hypothesis of causal relationships between
variables.
1) The principle of replication
2) The principle of randomization
3) The principle of local control

14. • The principle of replication, the experiment should
be repeated more than once.
• The principle of randomization provides protection,
when we conduct an experiment, against the effect of
extraneous factors by randomization.
• The principle of local control is divide the field into
several homogenous parts, known as blocks and then
each such block is dividend into parts equal to the
number of treatments.

15. EXPLORATORY AND CAUSAL RESEARCH
DESIGN

16. EXPLORATORY RESEARCH DESIGN
• Exploratory research design is normally used in
research whose purpose involves inquiry into new
products that should be developed, how the product
appeal will enhances its advertising, and how the
existing services can be improved.
• A major feature of exploratory design is
1)flexibility
2)adaptability
3)front end of total research design

17. • It is used to investigate a research problem that is not
clearly defined or understood. It provides researcher
with a deeper understanding of a research problem and
its context before further research can be carried out.
• This research design is also referred to as interpretive
research and helps answer question like “what”,
”where”, and “how”.

18. Characteristics of exploratory research
• Provides a groundwork for further research
• Is used to investigate issues that aren’t fully defined.
• Is unstructured in nature.
• Generally involves the use of qualitative research.

19. CAUSAL RESEARCH DESIGN
• Causal research is concerned with understanding the
connection between the cause and effect. Causal research is
often conducted through various controlled experiment to
allow for the testing of cause and effect. It explore the effect
of one variable on another.
• The researcher bias in the experiment consciously or
unconsciously.

20. DESCRIPTIVE AND EXPERIMENTAL
DESIGN

21. EXPERIMENTAL DESIGN
• Experimental research method can be defined as a method of
controlled observation of a succession of events.
• An experimental design is a test in which the researcher has a
control over one or more variables an manipulates them.
• It helps in establishing cause an effect relationship more
clearly than any other method.
• The experimental method make more accurate prediction.
• Experimental method is the best method considered to test
the hypothesis.

22. Descriptive research design
• Descriptive research design aims to accurately and systematically
describe a population, situation or phenomenon. It can answer
what, where, when and how question, but not describe why
question.
• A descriptive research design can use a wide variety of research
methods to investigate one or more variables.
Characteristics:
Statistical outcome
Basis for secondary research
Unrestrained variable

23. TYPES OF EXPERIMENTAL DESIGNS

24. • Experimental design refers to the framework or structure of
an experiment and as such there are several experimental
designs. We can classify experimental designs into two broad
categories.
i) informal experimental designs
ii) formal experimental designs.
Informal experimental designs are those designs that
normally use a less sophisticated form of analysis based on
differences in magnitudes.
Formal experimental designs offer relatively more control
and use precise statistical procedures for analysis. Important
experiment designs are as follows:.

25. Informal experimental designs:
(i) Before-and-after without control design.
(ii) After-only with control design.
(iii) Before-and-after with control design.
Formal experimental designs:
(i) Completely Randomized design (C.R. Design).
(ii) Randomized Block design (R.B. Design).
(iii) Latin square design (L.S. Design).
(iv) Factorial designs

26. INFORMAL EXPERIMENTAL DESIGN
Before-and-after without control design
i)single test group is selected
ii)Dependent variables is measured before treatment(x)
iii)Treatment is introduced and dependent variable is
measured(y)
The effect of the treatment would be equal to the level of the
phenomenon after the treatment minus the level of the
phenomenon before the treatment.
Treatment effect=Y-X

27. After-only with control design:
 Two groups or areas (test area and control area) are selected.
The treatment is introduced into the test area only.
 The dependent variable is then measured in both the areas at the
same time.
Treatment impact is assessed by subtracting the value of the
dependent variable in the control area from its value in the test
area.
Effect after treatment =Y
Effect without treatment=z
Treatment effect =y-z

28. Before-and-after with control design:
 Two areas are selected
 The dependent variable is measured in both the areas for an
identical time-period before the treatment.
 The treatment is then introduced into the test area only, and the
dependent variable is measured in both for an identical time-
period after the introduction of the treatment.
The treatment effect is determined by subtracting the change in
the dependent variable in the control area from the change in the
dependent variable in test area.
Before treatment After treatment
Test area X Y
Control area A Z
Treatment effect = (Y-X)-(Z-A)

29. FORMAL EXPERIMENTAL DESIGN
Completely Randomized design (C.R. design)
It Involves only two principles viz.,
• The principle of replication and
• The principle of randomization.
It is the simplest possible design and its procedure of analysis
is also easier. The essential characteristic of the design is that
subjects are randomly assigned to experimental treatments.
One-way analysis of variance (or one-way ANOVA) is used to
analyze such a design.

30. Replication: The replication design serves two purposes viz.,
it provides controls for the differential effects of the extraneous
independent variables and secondly, it randomizes any
individual differences among those conducting the treatments.
Randomization: All the population is defined and then from
the population a sample is selected randomly.
Further, requirement of this design is that items, after being
selected randomly from the population, be randomly assigned
to the experimental and control groups (Such random
assignment of items to two groups is technically described as
principle of randomization)

31.  Randomized block design (R.B. design)
• It is an improvement over the C.R. design. In the R.B. design
the principle of local control can be applied along with the
other two principles of experimental designs.
• In the R.B. design, subjects are first divided into groups,
known as blocks, such that within each group the subjects are
relatively homogeneous in respect to some selected variable.
• The main feature of the R.B. design is that in this each
treatment appears the same number of times in each block.
• The R.B. design is analyzed by the two-way analysis of
variance (two-way ANOVA) technique

32.  Latin square design (L.S. design)
• Latin square design (L.S. design) is an experimental design
very frequently used in agricultural research. The conditions
under which agricultural investigations are carried out are
different from those in other studies for nature plays an
important role in agriculture.
• The Latin-square design is one wherein each fertilizer, in our
example, appears five times but is used only once in each row
and in each column of the design.

33.  Factorial design:
Factorial designs are used in experiments where the effects of
varying more than one factor are to be determined. They are
specially important in several economic and social phenomena
where usually a large number of factors affect a particular
problem.
Factorial designs can be of two types:
(i) simple factorial designs
(ii) complex factorial designs
(i) Simple factorial designs: In case of simple factorial
designs, we consider the effects of varying two factors on
the dependent variable, but when an experiment is done
with more than two factors. It represent 2x2 factors.

34. ii)Complex factorial designs:
• Experiments with more than two factors at a time involve the
use of complex factorial designs.
• A design which considers three or more independent
variables simultaneously is called a complex factorial design.
• In case of three factors with one experimental variable
having two treatments and two control variables, each one of
which having two levels, the design used will be termed 2 × 2
× 2 complex factorial design
• Factorial designs are used mainly because of the two
advantages.
(i) They provide equivalent accuracy
(ii) They permit various other comparisons of interest.

35. VALIDITY OF FINDINGS
• Validity refers to how accurately a method measures what it
is intended to measure. If research has high validity, that
means it produces results that correspond to real properties.

36. INTERNALAN EXTERNAL VALIDITY
• Internal validity refers to the degree of confidence that the
causal relationship being tested is trustworthy and not
influenced by other factors or variables.
• External validity refers to the extent to which results from a
study can be applied to other situations, groups or events.

37. Variables in research
•In research , variables are any characteristics that can
take on different values, such as height, age,
temperature or test scores,
•Researchers often manipulate or measure independent
and dependent variables in studies to test cause-and-
effect relationships.

38. MEASUREMENT AND SCALING
TECHNIQUES

39. Measurement
• Measurement is defined as the assignment of numbers to
characteristics of objects or events according to rules.
• Data analysis is a statistical process done on the data
generated using scales. Hence, all measures should be
converted into quantitative terms by applying numbers.
Level of measurements:
a)nominal scale
b)ordinal scale
c)interval scale
d)ratio scale

40. Nominal scale
 Nominal scale is simply a system of assigning number
symbols to events in order to label them.
 Nominal scale are categorical scales used to identify or
categorize objects or persons or events.
 It is least powerful level of measurement.
 It indicates no order/distance relationship.
Example: age, gender, occupation.

41. Ordinal scale:
• Ordinal scale is a ranking scale that indicates ordered
relationship among the objects or events.
• The ordinal variable is similar to a categorical variable.
• The ordinal scale measure frequency, importance,
satisfaction, quality and experience.
• The primary advantage of using ordinal scale is the easy of
comparison between variables.
Example: The customers may be requested to rank the
products in terms of their preference for the products.
The number assigned to a particular object or event can never
be changed in ordinal scale.

42. Interval scale
• Interval scale is otherwise called as rating scale. It involves
the use of numbers to rate objects or events.
• The feature of this scale is that the difference between any
two scale values is identical.
Example: Temperature (Fahrenheit) scale, credit score

43. Ratio scale
• Ratio scale have absolute or true zero measurement.
• Ratio scale is a type of variable measurement scale which is
quantitative in nature.
• It allow any researcher to compare the intervals or
differences. This is unique feature of this scale.
Example: The temperature outside is 0-degree Celsius. 0
degree doesn’t means it’s not hot or cold, it is a value.
Speed.

44. Test of sound measurement
Test of validity: It indicates the degree to which an instrument
measures what it is supposed to measure.
Types:
a)Content validity – covering adequate information of the
topic
b)Criterion validity – ability to predict the outcome
c)Construct validity – predict the correlation with theoretical
prepositions

45. • Test of reliability: It providing consistent result with validity. It
should exhibit true and reliable value.
• Test of practicality: It can be judged using economy,
convenience, Interpretability.

46. Types of rating scale:
• Graphic rating scale: It is simple and is commonly used in
practice various prints are usually put along the line to form
range and the rater indicates the rating by simply making a
mark.
Example:
• Itemized rating scale/ numerical scale: It presents a series
of statements from which a respondent selects one as best
reflecting his evaluation.
Example: opinion about co-workers regarding resistance
a) almost involved in resistance b) often involved in resistance
c) sometimes involved in resistance d) infrequently involve in
resistance e) almost never

47. Dichotomous scale:
• It uses only 2 options to answer the question. Nominal scale
is used to obtain the response.
Example:
i) Are you having loan facility
a) yes b)no
i) Do you like the environment
a)like b)dislike

48. Category scale:
• It was multiple items to elicit single response used for
nominal scale.
Example:
Name the district in which you like a) Nagai b) Tanjore c) add
alone
Likert scale:(summated scale)
Express either favourable or unfavourable attitude using 5
point scale.
Example: opinion of satisfaction level
a) Highly dissatisfied b) dissatisfied c) neither satisfied nor
dissatisfied d) satisfied e) highly satisfied

49. Semantic differential scale:
• It was bipolar attributes to find the attitudes of the
respondents. It is a type of interval scale.
Example:
i) Manager response towards grievance
responsive----------------unresponsive
ii) Do you like the rules followed in your organization
like --------------------------dislike

50. Differential/Thurstone scale:
• Selection of items made by panel of judges. They evaluate the
relevant information to the topics area and definite
implication. It simply measure the opinion.
Example : share your feedback with us
1) I enjoy group discussion activities a)agree b)disagree
2) I am motivated to take part in group discussions a)agree
b)disagree

51. Cumulative scale/ louis Guttman analysis:
It consists of series of statement to which respondent express the
agreement or disagreement
Example : Item number Respondent score
Do you prefer
a product brand 4 3 2 1
On the price x x x x 4
Based on quality - x x x 3
X-agree; - disagree

52. Constant sum scale:
• The respondent are asked to distribute a given number of
points across various items. Mostly used for ordinal scale.
Example:
Choosing a toilet soap based on
1)fragrance –---
2)shape -----
3)colour ------
4)odour -----
5)price ------
total price 100

53. Ranking scale
Types of ranking:
Paired comparison scaling
Rank order scaling
Paired comparison scaling:
It is usually preferred for a small number of objects.
Paired comparison scaling as its name indicates involves
presentation of two objects and asking the respondents to select
one according to select criteria.
Paired comparison is used for ordinal data.
Paired choice for n objects N=[(n)(n-1)/2]
Example : n=10
N=[(10)(10-1)/2]
=[(10)(9)/2]
=45 (judgements were made)

54. Rank order scale/ forced choice scaling
• In rank order scaling is done by presenting the respondents
with several objects simultaneously and asked to order or
rank them based on a particular criterion.
Example :
preference of the laptop
* Sony 2
* HP 3
* Lenovo 5
*acer 1
*Samsung 4

55. Factor scale
• It helps to find the intercorrelation of the item.
• By reducing a data set from a group of interrelated variables
into a smaller set of uncorrelated factors
• Factor scale are particularly useful in uncovering latent
attitude dimensions and approach scaling through the
concepts of multiple- dimension attributes.
• An important factor scale based on factor analysis is semantic
differential and other one is multidimensional scaling.

56. CONSTRUCTION OF INSTRUMENT
• A research instrument is a tool used to collect, measure, and
analyze data related to your subject. Research instrument can
be tests, survey, questionnaire, or even checklist.
The Steps in constructing a research:
Step 1: Identify and develop your topic
Step 2: Find background information
Step 3: Use catalogs to find books and media
Step 4: Use databases to find journal articles
Step 5: Find internet resources
Step 6: Evaluate what you find

57. VALIDITY AND RELIABILITY OF
INSTRUMENT
• Validity and reliability are concepts used to evaluate the
quality of research. They indicate how well a method,
technique or test measures something.
Validity: Validity is about the accuracy of a measure. Validity
is harder to assess, but it can be estimated by comparing the
results to other relevant data's. The validity of a measurement
can be estimated based on three main types of evidence:
i) construct
ii) Content
iii) Criterion

58. • Reliability : Reliability is about the consistency of a measure.
Reliability refers to how consistently a method measure
something.
Types:
1.Test – retest
2.Interrater
3.Internal consistency