Transcript MEASUREMENT - Universiti Sains Malaysia

MEASUREMENT
Measurement
“If you can’t measure it,
you can’t manage it.”
Bob Donath,
Consultant
Measurement
Selecting
measurable phenomena
Developing a set of
mapping rules
Applying the mapping rule
to each phenomenon
What is to be measured?
CONCEPTS/CONSTRUCTS/VARIABLES

Operational Definitions
- Dimensions
- Elements

Scales
CONCEPT
A GENERALIZED IDEA ABOUT A
CLASS OF OBJECTS,
ATTRIBUTES, OCCURRENCES,
OR PROCESSES.
(e.g., Technology, Dynamism, Adoption,
Learning)
CONSTRUCT


An image or idea specifically invented for a given
research and/or theory-building purpose
Higher level concepts for specialised scientific
explanatory purposes that are not directly
observable and for thinking about and
communicating abstractions
Concepts and constructs are used at theoretical levels
VARIABLE
Used at empirical level
 Accept numeral or values for the purpose of
testing and measurement

OPERATIONAL DEFINITION
A definition
for a construct stated in terms of
specific criteria for testing or measurement
Specifies
what the researcher must do to
measure the concept/construct under
investigation
SCALE
- Definition
SERIES OF ITEMS
 ARRANGED ACCORDING TO VALUE
 FOR THE PURPOSE OF
QUANTIFICATION
 A CONTINUOUS SPECTRUM

SCALE PROPERTIES
UNIQUELY CLASSIFIES
 PRESERVES ORDER
 DISTANCE/EQUAL INTERVALS
 NATURAL ORIGIN (ZERO)

Types of Scales
Nominal
Ordinal
Interval
Ratio
NOMINAL SCALE
Nominal Scales
Mutually exclusive
and collectively
exhaustive
categories
 Exhibits the
classification
characteristic only

NOMINAL SCALE
PROPERTIES
UNIQUELY CLASSIFIES
Male/Female
 Academic/Admin
 Asian/European
 Strategy types
 Adopters/Non Adopters

Levels of Measurement
Nominal
Ordinal
Interval
Ratio
Classification
ORDINAL SCALE
Ordinal Scales
Characteristics of
nominal scale plus
an indication of
order
 Implies statement
of greater than and
less than

ORDINAL SCALE
PROPERTIES
UNIQUELY CLASSIFIES
PRESERVES ORDER
Win, Place & Show
 Podium/Grid positions
 Ranking

Levels of Measurement
Nominal
Ordinal
Interval
Ratio
Classification
Classification
Order
INTERVAL SCALE
Interval Scales
Characteristics of
nominal and ordinal
scales plus the
concept of equality
of interval.
 Equal distance
exists between
numbers

INTERVAL SCALE
PROPERTIES
UNIQUELY CLASSIFIES
PRESERVES ORDER
EQUAL INTERVALS
Consumer Price Index (Base 100)
 Fahrenheit Temperature
 Assessment of attitude, beliefs, intention

Levels of Measurement
Nominal
Classification
Ordinal
Classification
Order
interval
Classification
Order
Ratio
Distance
RATIO SCALE
Ratio Scales


Characteristics of
previous scales plus an
absolute zero point
Examples
 Weight
 Height
 Number of children
RATIO SCALE PROPERTIES
UNIQUELY CLASSIFIES
PRESERVES ORDER
EQUAL INTERVALS
NATURAL ZERO
Weight and distance
 Age, years of service

Levels of Measurement
Nominal
Classification
Ordinal
Classification
Order
Interval
Classification
Order
Distance
Ratio
Classification
Order
Distance
Natural Origin
Goodness of Measures

Accurately measuring what
actually the concept one sets out to
measure
 Should
be easy and efficient to use
Evaluating
Measurement Tools
Validity
Criteria
Practicality
Reliability
Validity
The ability of a scale to measure
what was intended to be
measured.
Validity Determinants
Content
Criterion
Construct
Increasing Content Validity
Literature
Search
Expert
Interviews
Content
Question
Database
Group
Interviews
……Goodness of Measures

Validity
 Content Validity
 Includes Face Validity
 How well the dimensions and elements
of a concept have been delineated
 Professional agreement that a scale
logically appears to accurately measure
what it is intended to measure
Validity Determinants
Content
Construct
Increasing Construct Validity
New measure of trust
Known measure of trust
Empathy
Credibility
……Goodness of Measures

Construct Validity – when empirical evidence
generated by a measure is consistent with the
theoretical logic of the concept
 Convergent Validity – the measure should
“converge” with other similar measures
 Discriminant Validity – when the measure
has low correlation with measures of
dissimilar concept
Judging Criterion Validity
Relevance
Freedom from bias
Criterion
Reliability
Availability
Criterion-Related Validity


Concurrent – When the scale discriminates
individuals who are known to be different; A
type of criterion validity whereby a new
measure correlates with a criterion measure
taken at the same time.
Predictive Validity – Ability to differentiate
among individuals with reference to a future
criterion
VALIDITY
Validity
FACE OR CONTENT
CRITERION VALIDITY
CONCURRENT
CONSTRUCT VALIDITY
PREDICTIVE
Reliability
The degree to which measures are
free from random error and therefore
yield consistent results.
Reliability Estimates
Stability
Internal
Consistency
Equivalence
Reliability Estimates
Stability
Internal
Consistency
Equivalence
… Reliability

Stability of Measures
 Test-Retest Reliability – the
administering of the same scale or
measure to the same respondents at
two separate points in time

Parallel-Form Reliability - when
responses on two comparable sets of
measures tapping the same construct
are highly correlated
Reliability Estimates
Stability
Internal
Consistency
Equivalence
Equivalence

Variations at one point in time among
observers and samples of items
Reliability Estimates
Stability
Internal
Consistency
Equivalence
… Reliability

Internal Consistency Measures
 Interitem Consistency Reliability where items that are independent
measures of the same concept correlate
with one another.

Split-Half Reliability – reflects the
correlations between two halves of an
instrument
RELIABILITY
RELIABILITY
STABILITY
TEST RETEST
INTERNAL CONSISTENCY
EQUIVALENT FORMS
SPLITTING HALVES
Understanding Validity and
Reliability
Practicality
Economy
Convenience
Interpretability
SENSITIVITY
 A measurement
instrument’s ability to
accurately measure variability in
stimuli or responses.
Rating Scales
Used to elicit responses with regard to
the object, event, or person studies:
Dichotomous scale
Category scale
Likert scale
Numerical scale
Semantic differential scale
…..Rating Scales
Itemised rating scale
Fixed or constant sum rating scale
Stapel scale
Graphic rating scale
Consensus scale
Ranking Scales
To tap preferences between two or more
objects or items

Paired Comparison

Forced Choice

Comparative