Concept, importance and scales of measurement

1. B.Ed. II Year
Paper II
Assessment for Learning

2. Main Points of Discussion
Concept of Measurement
Characteristics of Measurement
Importance of Measurement
Scales of Measurement

3. Measurement
Measurement defined as the process of assigning a score
that represents the degree to which some trait,
characteristics or behaviour is associated with person.
Measuring any aspect is to state the particular attributes or
variables(age,height,weight, length, time) in terms of
quantity and quantity is expressed through the number of
unit of measurement (like year for age).
Measurement means quantitative description of data.

4. Definition
Campbell: “Measurement is the assigning of numerals
to objects or events according to rules.”
M.S.Stevens : “Measurement is the process of
assigning numbers to objects according to certain
agreed rules.”

5. Characteristics of Measurement
Process of Quantification:
Measurement involves the process of quantification. In the process
of measurement, numerals are used to represent quantities of the
attribute. Quantification indicates how much or to what extent that
particular attribute is present in a particular object.

6. A Complex Process:
The process of measurement in behavioural sciences is difficult as well
as complex. The trait or attribute is not directly measured by the scale
but the trait is measured indirectly by the behaviours.
NoDefinite Units: The units are not definite in educational
measurement. We may not obtain the same value for every person. It is
very much dependent on psychological and educational tests which vary
in content and objective. An individual may obtain different scores in
different intelligence tests.

7. Sense of Infinity: Measurement in behavioural sciences conveys
a sense of infinity. It means we cannot measure the whole of an
attribute of an individual.
Process of Assigning Symbols:
Measurement, in general term, is the process of assigning symbols to
observations in some meaningful and consistent manner. Symbols
are supposed to express a definite scale position because it is
associated with the word ‘measure’.

8. In the process of measurement the investigator does not assign
numbers of his own choice, but according to certain fixed and explicit
rules.
Mental Measurement is often Subjective:
The accuracy of measurement depends upon the person who
measures it. It also depends on various factors like conditions of
testing, type of test items, defects in language, physical and
emotional conditions of the testees etc.

9. No Absolute Zero Point:
In educational measurement there is concept of no absolute zero
point. It is relative to some arbitrary standard. A student has
scored zero in a test or subject. It does not mean that he does not
know anything of that test or subject. We cannot claim that a boy
with an I.Q. of 110 is twice as intelligent as a boy with an I.Q. of 55.

10. Importance of Measurement
For Diagnosis: It diagnosis the nature of difficulties. The
weakness of the learner can be identified through measurement.
The remedial instruction can be prepared on the basis of
diagnosis.
For Prediction: It predicts success. Success and failure of the
student is predicted through measurement . For instance, a
student who always gets high scores in all his subjects may
mean that he is sure to pass and passing means success.

11. For determining achievement: It measures students’ achievement.
Students’ achievement can be determined whether he has reached
the goals of the learning tasks or not through measurement and
evaluation.
For evaluation: It evaluates instruction. The effectiveness or
ineffectiveness of instruction is ascertained through measurement .
For classification and Comparison: Students are classified for
different course or programmes according to their achievement and
ability. Educators classify them brilliant, average or backward on the
basis of educational measurement.

12. For Research: Measurement is an essential element of research. No
research work in education and psychology is possible without some
sort of measurement.

13. What is the Scale?
A scale is a device or an object used to measure or quantify any
event or another object.
Scale/Levels of Measurements
There are four different scales of measurement. The data can be
defined as being one of the four scales. The four types of scales
are:
● Nominal Scale
● Ordinal Scale
● Interval Scale
● Ratio Scale

14. Nominal Scale
Nominal variables (also called categorical variables) can be placed into
categories. They don’t have a numeric value and so cannot be added,
subtracted, divided or multiplied. They also have no order; if they appear to
have an order then you probably have ordinal variables instead.
Example:What is your gender? Male- Female, What is your hair colour?
Ordinal or Rank Scale
The ordinal scale contains things that you can place in order. For example,
hottest to coldest, lightest to heaviest, richest to poorest. Basically, if you
can rank data by 1st, 2nd, 3rd place (in school for prize distribution), then
you have data that’s on an ordinal scale.
Example:Ratings in restaurants

15. Interval Scale
Interval scales are numeric scales in which we know both the order
and the exact differences between the values. The classic example
of an interval scale is Celsius temperature because the difference
between each value is the same. For example, the difference
between 60 and 50 degrees is a measurable 10 degrees, as is the
difference between 80 and 70 degrees.With interval data, we can add
and subtract, but cannot multiply or divide. (teaching -learning
situation,educational research)

16. Ratio Scale
It is the most refined scale among the four basic scales.
Ratio level variable have all of the characteristics of
Nominal,ordinal and interval variables but also have an
absolute zero point representing complete absence of the
property being measured. It is used in physical sciences and
less frequently in behavioural sciences.These variables can be
meaningfully added,subtracted, multiplied and divided
(maintaining the cumulative records of the students).

17. Levels of Measurement
Named + ordered +
Named + ordered + Named + ordered +
Propotionate interval propotionate interval
between variables between variables +
Named + ordered can accommodate
Variables true zero
Named variables
Nominal
Ordinal
Interval
Ratio

18. •Nominal Scale ( 1.Identification)
•Ordinal Scale (1+ 2.ordering/Sequencing )
•Interval Scale (1+2+3.add/subtract, no absolute
zero)
•Ratio Scale (1+2+3+4. Presence of Absolute
zero)