CHAPTER FIVE Measurement and scaling techniques.
•
CHAPTER FIVE
Measurement and scaling techniques.
CHAPTER FIVE
Measurement and scaling techniques.
qMeasurement
in research.
qMeasurement
scales.
qSources
of error in measurement.
qTests
of sound measurement.
qTechnique
of developing measurement tools.
qScaling.
qMeaning
of scaling.
qScale
classification bases.
qImportant
scaling techniques.
qScale
construction techniques.
•
•Measurement
•Measurement
is Values made meaningful by counting into specific units.
Measurements act as labels which make those values more
useful in terms of details. For example, instead of saying that
someone is tall, we can specify a measurement and specify that
the individual is 6 feet tall.
•measurement
of length, height, money amounts, weight, volume, area, pressures, temperature
readings (in degrees Fahrenheit) etc.
•
•Measurement
is defined as the act of measuring or the size of something. Measurement is a
procedure for assigning symbols, letters, or numbers to practical properties of
weight and height, length and width, or distance in km or miles, and
temperature degree, according to rules. Or the act or process
of measuring, a figure, extent, or amount obtained by
measuring: dimension, measure.
•Number property
1 Female
1 Male
§We
could have also assigned
M
Male
F
Female
•Measurement
:
•Measurement
is the process of observing and recording the observations that are collected
as part of research. The recording of the observations may be in terms of
number or other symbol to characteristics of objects according to certain
prescribed rules.
•Measurement
is a
procedure for transferring
symbols,
letters, or numbers to practical goods of weight and height, length and width, or
distance in km or miles, and temperature degree, according to rules. Or the act
or process of measuring, a figure, size, or amount obtained by measuring, dimension,
measure.
•Measurement
is defined as the act of measuring or the size of something.
•
•
Measurement scales.
Measurement scales (nominal scale, ordinal scale, interval scale, ratio scale)
Measurement scales.
Measurement scales (nominal scale, ordinal scale, interval scale, ratio scale)
•Scaling is the branch of measurement that
involves the level or degree or amount or size of metric units , Scaling
describes the procedures of assigning of numbers or symbols (i.e., quantitative
measures) to subjective abstract concepts (or properties of objects)
•LEVEL OF MEASUREMENT: The
most widely used classification of measurement scales or Scale Properties are
of the following.
•
Nominal scale
•
Ordinal scale
•Interval
scale
•Ratio
scale
•
•Nominal
Scale:
•Nominal
Scale: A nominal scale is the simplest of the four scale types and in which the
numbers or letters assigned to objects serve as labels for identification or
classification.
•Example:
What is your sex?
qMale
qFemale
• Example: Males = 1, Females = 2
Drinks A = Pepsi Cola, Drink B = 7-Up, Drink C = Miranda
Sales
Zone
A = Mogadishu,
Sales
Zone B = Kismayo§ Males = 1, Females = 2
•
•Ordinal Scale:
•Ordinal
Scale: Ordinal measurements describe order, but not relative size or degree of
difference between the items measured In this scale type, the numbers
assigned to objects or events represent the rank order (1st,2nd,3rd,etc) of the
entities assessed.
•Which one of the following media
influences your purchasing decisions the most?
§Television
§Radio
§Newspapers
§Magazines
§Internet
Possess
order but not distance or origin
Numbers assigned
preserve the order relationship (rank) and the ability to distinguish
between elements according to a single attribute & element
ordinal
scale
and may also use names with an order such as: ❖ “Bad”, “medium” and “good” ❖
“very satisfied”, “satisfied”, “neutral”, “unsatisfied”, “very unsatisfied”
•
•Example of an ordinal scale:
•Example
of an ordinal scale:
•The
result
of a horse race, which says only which horses arrived first, second, or third
but include no information about race times.
•Examples
of Ordinal:
•Career
Opportunities
= Moderate, Good, Excellent Merit = A grade, B grade, C grade, D Investment
Climate = Bad, inadequate, fair, good, very good .
• An
ordinal scale is more powerful than a nominal scale in that the numbers possess
the property of rank order
•How long do you spend reading newspapers
on a typical weekday?
§Less
than 5 minutes
§5
minutes to less than 15 minutes
§15
minutes to less than 30 minutes
§30
minutes or more
§
•Interval Scale :
•Interval Scale :
• An interval scale is a scale that
not only arranges objects or alternatives according to their respective degrees
but
also distinguishes this ordered arrangement in units of equal intervals (i.e.
interval scales indicate order (as in ordinal scales) and also the distance in
the order).
•Possess the characteristic of order and
distance
•DOES NOT possess origin
•Numbers are assigned in such a way that
they protect
both
the order
and distance
but do not have a unique starting point
Example:
temperature scale -
•50 degree
F
is twice as warm as 25o F
•10 degree C is not twice as warm as -3.9o C
Permissible
mathematical operations
•
(+)
Mean, average déviation,
standard
déviation,
corrélation, t
F
example
:
•Interval
data. Suppose we are given the following temperature readings (in degrees
Fahrenheit):
•58°,
63°, 70°, 95°, 110°, 126° and 135°. In this case, we can write 100° > 70° or
95° < 135° which simply means that 110° is warmer than 70° and that 95° is
cooler than 135°. We can also write for example 95° – 70° = 135° – 110°,
•Ratio
scale
•Ratio
scale: ratio scale is a scale that possesses absolute rather than relative
qualities and has an absolute zero.
•Examples:
§Money
§Weight
§Distance
§Temperature
on the Kelvin scale
RATIO SCALE
:
•Possess the characteristic of order
distance and origin
•
Numbers
are assigned in such a way that they preserve both the order
distance and
origin
•Example: length (KM scale), weight (KG
scale)
•50 KG is twice as heavy as 25 KG
•110.24 pound is twice as heavy as 55.12
pound
•
Permissible
mathematical operations: ALL
•
•Sources
of Error in Measurement:
•Sources
of Error in Measurement:
•Measurement
error is defined as the difference between the distorted or disfigures
information and the undistorted information about a measured product, like
Input error, signal transmission error, signal communication error, converter
error, computer error, indication error expressed in its measure. In short, an
error is defined as (untrue, wrong, false, no go) value at the output of a
measurement system
•Source
of
Error in measurement is the amount of deviation in a physical quantity that take
places as a
result of the process of measurement or approximation.
•Another
term
for error is uncertainty
or to express
this uncertainty in the measurement process or Measurement should be precise
and unambiguous in a perfect research study.
•The
following
are the possible sources of error in measurement.
•Sources
of Error in Measurement:
•The
following are the possible sources of error in measurement.
qRespondent
qSituation
qMeasurer
qInstrument
Respondent: At
times the respondent may be :
•
reluctant to express strong negative feelings
•or it
is just possible that he may have very little knowledge but may not admit his
ignorance.
•All
this reluctance is likely to result in an interview of ‘guesses.
•other
factors like fatigue, boring, anxiety or nervousness, etc. may limit the
ability of the respondent to respond accurately and fully.
•
•
•Continue
•Situation:
•For
instance, if someone else is present, he can distort or deform responses by
joining in by being present.
• If
the respondent feels that uncertainty is not assured, he may be reluctant to
express certain feelings.
•Any
condition which places a nervous tension on interview can have serious effects
on the interviewer-respondent rapport.
•
Situational factors may also come in the way of correct measurement.
•
•Continue
•Measurer:
•The
interviewer can deform responses by rewritings or reordering questions.
•
His behaviour, style and looks may encourage or discourage certain replies from
respondents.
•Careless
mechanical processing may distort the findings.
•
Errors may also move quietly in because of incorrect coding, faulty vacant
and/or statistical calculations, particularly in the data-analysis stage.
•Continue
•Instrument:
• Error
may take place because of the imperfect measuring instrument.
•The
use of complex words, beyond the understanding of the respondent, ambiguous
meanings, poor printing, inadequate space for replies, response choice
omissions, etc.
•
Few things that make the measuring instrument imperfect and may result in
measurement errors.
•Another
type of instrument deficiency is the poor sampling of the universe of items of
concern.
•Researcher
must know that correct measurement depends on successfully meeting all of the
problems listed above.
•Researcher
must, to the size possible, try to eliminate, neutralize or otherwise deal with
all the possible sources of error so that the final results may not be
contaminated.
•
•Tests
of sound measurement.
•Tests of Sound Measurement:
•Sound
measurement must meet the tests of validity, reliability and practicality.
•In
fact, these are the three major considerations one should use in evaluating a
measurement tool.
1.Validity refers
to the extent to which a test measures what we actually wish to measure.
2.Reliability has
to do with the quality of measurement and has to do with the accuracy and
precision of a measurement procedure
3.Practicality is
concerned with a wide range of factors of economy, convenience, and
interpretability” We briefly take up the relevant details concerning these
tests of sound measurement.
•Three
Types of Validity
•
We briefly take up the relevant details concerning these tests of sound
measurement as of the following :
1.Test of Validity : Test
validity refers to the degree to which the test actually measures what it
claims to measure test validity is also
the extent to which inferences, conclusions, and decisions made on the basis of
test scores are appropriate and meaningful
2. Test of Reliability : Test
reliability refers to the degree to which a test is consistent and stable in
measuring what it is intended to measure as to understand the basics of test
reliability
3. Test of Practicality : The
practicality characteristic of a measuring instrument can be judged in terms of
economy, feasibility and interpretability. From the operational point of view,
the measuring instrument ought to be practical i.e., it should be economical,
convenient and interpretable.
•Certainly
consider three types of validity in this connection:
I.Content validity.
II.Criterion-related validity.
III. Construct validity.
•1. Content validity
•Content validity is
the extent to which a measuring instrument provides adequate coverage of the
topic under study.
•
If the instrument contains a representative sample of the universe, the content
validity is good.
•It
can also be decided by using group of persons who shall judge how well the
measuring instrument meets the standards, but there is no numerical way to
express it.
•2. Criterion-related validity (standard
factor)
•Criterion-related
validity is
important factor or measure relates to
our ability to predict some outcome or estimate the existence of some current
condition.
•This
form of validity be a sign of the success of measures used for some empirical
or experiential estimating purpose.
•The
concerned criterion or standard must possess the following qualities:
q
Relevance:
(A
criterion or measure or standard is relevant
or appropriate if it is described in terms we judge to be the proper
measure.)
qFreedom from bias:
(Freedom from bias is achieved when the criterion or measure or
standard gives each subject an equal
opportunity to score well.)
qReliability: (A
reliable criterion decisive factor or
measure is stable or reproducible.)
qAvailability:
(The information specified by the criterion must be available.)
q
•3.
Construct validity
•Construct
validity is
the most complex and abstract or theoretical or conceptual .
•A
measure is said to possess construct validity to the degree that it confirms to
predicted correlations with other theoretical propositions or plans.
•Construct
validity is the degree to which achieves on a test can be accounted for by the
explanatory constructs of a sound theory.
• For
determining construct validity, we associate a set of other propositions plans
or with the results received from using our measurement instrument.
•If
measurements on our plan scale correlate in a predicted way with these other
propositions, we can conclude that there is some construct validity.
•If
the above stated criteria and tests are met with, we may state that our
measuring instrument is valid and will result in correct measurement; otherwise
we shall have to look for more information and /or resort to exercise of
judgment.
•TECHNIQUE
OF DEVELOPING MEASUREMENT TOOLS
•The
technique of developing measurement tools involves a four-stage process,
consisting of the Following:
a) Concept development.
b) Specification of concept dimensions.
c) Selection of indicators.
d) Formation of index.
•
•Technique
of Developing Measurement Tools:
Measurement Tools involves a
Four-Stage Process :
a)
Concept
development:
This is the first step. the researcher should have a complete understanding of
all the important concepts relevant to his study. This step is more applicable
to theoretical studies compared to practical studies where the basic concepts
are already established beforehand.
b)
Specification
of concept dimensions:
the researcher is required to specify the dimensions of the concepts, which
were developed in the first stage of concept development . This is achieved
either by adopting an perceptive or understanding approach or by an empirical or experimental correlation of the individual
dimensions with that concept and/or other concepts.
c)
Indicator
selection: In
this step, the researcher has to develop the indicators that help in measuring
the elements of the concept. Indicator is a way to measure or a
thing that indicates the state or level of something, these indicators include
specific
questionnaires,
scales, and other devices,
which help to measure the respondents opinion, way of thinking,
knowledge,
expectation, etc. Using more than one indicator lands
stability and improves the validity of the scores.
d) Index formation:
Here, the researcher combines the different indicators into an index. In case,
there are several dimensions of a concept the researcher needs to combine them.
•Scaling
•Scaling is
the process of measuring things or individual with respect to
quantitative characteristics.
•Certain
methods of scaling permit estimation of sizes or importance on a scale,
while other methods provide only for relative ordering of the things.
•There
are four measurement scales (or types of data): These are simply ways to
categorize different types of variables.
1.nominal,
2.ordinal,
3.interval
and
4.
ratio.
Scaling
is the branch of measurement that involves the construction of an instrument
that bracket together qualitative constructs with quantitative metric units.
●
•
•Meaning
of Scaling
•Meaning
of scaling
•Scaling
describes the procedures of planning numbers to various degrees of opinion,
attitude and other concepts. For example, a scaling technique might involve
estimating individuals' levels of a central dimension of human personality
theories, or the identified quality of products.
•Meaning
of Scaling is
the process of measuring or ordering units or things or individual
with respect to quantitative characteristics.
•Certain
methods of scaling permit estimation of sizes or importance on a scale,
while other methods provide only for relative ordering of the entities.
•The level
of measurement is the type of data that is measured.
•The
word scale is sometimes (including in academic literature) used to refer to
another complex measure, that of an index or directory. Those
concepts are however different.
•Meaning
of Scaling
•Scaling
describes the procedures of assigning numbers to various degrees of opinion,
attitude and other concepts. This can be done in two ways .,
1.making
a judgment about some characteristic of an individual and then placing him
directly on a scale that has been defined in terms of that characteristic and
2.Constructing
questionnaires in such a way that the score of individual’s responses assigns
him a place on a scale. It may be stated here that a scale is a continuum,
consisting of the highest point (in terms of some characteristic e.g.,
preference, favorableness, etc.) and the lowest point along with several
intermediate points between these two extreme points.
•Scaling
is the branch of measurement that involves the construction of an instrument
that associates qualitative constructs with quantitative metric units.
•Scaling
evolved out of efforts in psychology (Psychology is the study of mind and
behavior)and education to measure "unmeasurable" constructs like
totalitarianism and self value.
•Scale
classification bases
•The
Scale Classification Bases can be categorized on the following
bases.
1.Subject orientation
2.Response form
3.Degree of subjectivity
4.Scale properties
5.Number of dimensions
6.Scale construction techniques
•Subject
orientation: In
this, a scale is planned to measure the characteristics of the respondent who
completes it or to estimate the motivation aim that is presented to the
respondent.
•Response
form: In
this, the scales can be classified as categorical or comparative. Categorical
scales (rating scales) are used when a respondent scores some object without
direct reference to other objects. Comparative scales (ranking scales) are used
when the respondent is asked to compare two or more objects.
•Scale
classification bases
• Degree
of subjectivity:
In this, the scale data is based on whether we measure subjective(one-sided)
personal favorites or just make non-favorite judgments. the respondent is asked
to select which person or solution he favors to be employed, whereas
in the last case he is simply asked to judge which person or solution will be
more effective without reflecting any personal preference.
•Scale
properties: In
this, the scales can be classified as nominal, ordinal, interval and ratio
scales. Nominal scales simply classify without indicating order, distance or
unique origin. Ordinal scales indicate magnitude relationships of ‘more than’
or ‘less than’, but indicate no distance or unique origin. Interval scales have
both order and distance values, but no unique origin. Whereas, ratio scales
possess all these features.
•Number
of dimensions:
In this, the scales are classified as ‘uni-dimensional’ or ‘multi-dimensional’.
In the former, only one attribute of the respondent or object is measured,
whereas multi-dimensional scaling recognizes that an object might be
described better by using the concept of an attribute space of ‘n’ dimensions,
rather than a single dimension continuum.
•
•Scale
classification bases
•Scale
construction techniques:
This can be developed by the following five techniques.
1.Arbitrary approach
2.Consensus approach
3.Item analysis approach
4.Cumulative scales
5.Factor scales
•Arbitrary
approach: In
this, the scales are developed on ad hoc basis. It is the most widely used
approach.
•Consensus
approach: In
this, a panel of judges evaluates the items chosen for inclusion in the
instrument regarding whether they are relevant to the topic area and
unambiguous in implication.
•Item
analysis approach:
In this, a number of individual items are developed into a test that is given
to a group of respondents. Post administering the test, total scores are
evaluated, and the individual items are analyzed to determine which items
discriminate between persons or objects with high and low total scores.
•Cumulative
scales:
These are chosen on the basis of meeting the requirements to some ranking of
items with rising and sliding discriminating power.
•Factor
scales: This
can be constructed on the basis of inter-correlations of items indicating a
common factor accounts for the relationship between items.
•
•Important
of scaling
•IMPRTANT
SCALING TECHINQUES
•IMPRTANT
SCALING TECHINQUES
•A rating
scale is
a set of categories designed to bring out information about a quantitative or a
qualitative characteristic. , is a general and largely language concept used
for rating things, people, places, ideas, and so on
•In
terms of important scaling techniques We now take up some of the important
scaling techniques often used in the context of research specially in context
of social or business research.
•Rating scales: the
rating scale involves qualitative description of limited number of aspects of a
thing or characteristics of a person.
•When
we use rating scale or categorical scale, we judge an object in absolute terms
against some specified criteteria example we judge properties of objects
without reference to their similar objects.
•A categorical variable
(sometimes called a nominal variable) is one that has two or more categories.
For example, gender is a categorical variable
having two categories (male and female).
•How do you like the product?
•like-dislike
,above average, average, below average, or other classifications with more
categories such as neutral, dislike
somewhat, dislike very much ,excellent—good—average—below average—poor”,
“always—often—occasionally —rarely—never”, and so on.
•
•Scale Construction Techniques:
•Scale Construction Techniques:
•In
social science studies, while measuring attitudes of the people we generally
follow the technique of preparing the Opinionnaire (or attitude scale) in such
a way that the score of the individual responses allocates him a place on a
scale. Under this approach, the respondent expresses his agreement or
disagreement with a number of statements relevant to the issue.
•
While developing such statements, the researcher must note the following two
points:
1.that
the statements must bring out responses which are sensitively related to the
attitude being measured.
2.That
the statements need be discriminate not simply between extremes of attitude but
also among individuals who differ slightly.
•
•
•Thank
you for your understanding and cooperation
Yours
Prof.Omar Abdi
Mohamed
Lecturer
•
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