MEASUREMENT
Wiersman and Jurs
(1985),define measurement as a process of assigning numbers of numerals to
object or events according to rules .The numbers represents some specific
characteristic of the object or event. A numeral can be a symbol such as 1, 2,
3, 4 etc. However the numeral itself has no relevance to measurement until it
is assigned quantitative meaning.
Babyegea (1998) defines
measurement to be a process of obtaining and assigning numerical description of
the degree to which an individual processes a particular characteristics. In
teaching and learning process measurement
involves scoring the test and
giving a student a score or a mark he/she has obtained e.g Assigning 60 to a
particular student is what makes testing to be a measuring process.
SCALES
OF MEASUREMENT
(i).Nominal
measurement scale
In this case, numbers
has got no meaning rather they are used
for identification and categorization process of objects or attributes. Eg In
soccer- players are being given numbers in order to be identified like
1-
Goalkeeper
2-
First basemen
3-
Second basemen
N.B The numbers do not
mean anything, the assignment in arbitrary (arbitrary means that zero does not
indicate the complete absence of property), and no arithmetic of these numbers
in meaningful e.g One plus two does not
equal to three since first player plus
the second does not lead to the third player. Therefore nominal numbers are
used for identification purposes.
(ii).
Ordinal scale
Is a scale used for
classifying and assigning rank order. Eg ranking individuals in a class
according to their test scores. Student scores could be ordered from first,
second, third and so forth to the lowest score.
Advantages
a)Gives more
information than nominal measurement.
Disadvantages
(a)The units of ordinal
scale are most likely unequal- the difference between the first person and the
second and the third does not necessarily vary equally. The number of points
separating the first and the second students probably not be equal to the number
separating the fifth and sixth students.
(b)No mathematical
operation can be performed through this scale since addition and subtraction of
such units yield meaningless numbers. This is because the interval between
numbers is unknown, depends on performance. One can be the first if is the only
one getting 30 or 50or 70 or100.
(iii).
Interval scale/Equal interval/Equal unit Measurement.
The interval between
two values is fixed or is in equal means. The scale contains properties from
nominal and ordinal scale. E.g Thermometers and calendar years. The difference
in temperature between 10 and 20 is the same as that between 47 and 57degrees
centigrade. Likewise the difference in length of time between 1946 and 1948
equals to that between 1973 and 1975. These measures are defined in terms of
physical properties such that these intervals are equal.
Advantages
(a)Some mathematical
oparations can be performed e.g Addition and subtraction.
Disadvantages
(a)We cannot multiply or divide because we do not
know the absolute upper and lower
limits. E.g Temperature 0 does not mean that there is no temperature, 100 in
Math does not mean that one has all abilities in math.
(iv).Ratio
scale
The scale is used for
measuring height, volume, weight, distance etc. it is rarely used and achieved
in educational assessment either in cognitive or affective areas. This is
because; unlike in an interval scale in the ratio scale, zero point is not arbitrary. A score indicates the
absence of the quality being measured.
Advantages
a)Allows comparison
E.g Asha is ½ times as taller as her young sister Anna.
However we can seldom say that one’s intelligence or achievement is ½ times as
greater as that of another person.
SUMMARY
Nominal Scales:
categorize and order
Ordinal scales: Categorize
and order
Interval Scales:
Categorize, order and establish and equal unit in the scale
Ratio Scale: Categorize
order, establish and equal unit and
contain a true zero point.
N.B: Educational
testing falls usually somewhere between Ordinal and Interval scales in
sophistication.
FUNCTIONS OF MEASUREMENT IN EDUCATION
Educational measurement
saves specific functions. These functions can be grouped under 3 general
categories, INSTRUCTIONAL, GUIDANCE and
COUNCELLING, ADMINISTRATIVE PURPOSES.
INSTRUCTIONAL
(i)Motivate and enhance
learning to students. An appropriate and fair test enhances students’ morale to
learn while unfair one discourages them, so as teachers we need to be very
careful when constructing a test.
(ii)Test provide feedback
to the teacher on the nature of the students. The results may be used for
diagnosis of possible student’s weakness and evaluation of student’s
performance.
(iii)Provide feedback
on the effectiveness of instruction (teaching and learning process)
Has the instruction been effective?
§ Is
there certain content that was poorly covered?
§ Student’s
misconception due to confused instruction? (for improvement to be made)
GUIDANCE
AND COUNCELLING
(I)Students can be
guided on how to study depending on the frequency of their scores.
ADMINSTRATIVELY
(II)Measurement can
save a function of correcting administrative issues often related to program
evaluation. Test information indicates weather or not student needs are being
met. In some schools, school boards use student’s test results for the
evaluation of the teaching performance or sorting students in streams e.g stream A- Intelligent, B- Moderate etc.
administratively decisions can be easily made from test results.
EVALUATION
(Answers the questions how good?)
Is a systematic process of observing,
collecting, analyzing and interpreting information to determine the extent to
which students are achieving what the teacher intends them to achieve.
Teacher’s intentions are normally expressed as instructional objectives.
Generally evaluation deals with value judgment on the entire process of
testing, measuring and evaluating the desirability of the results.
N.B
Evaluation does not always base on measurement, sometimes can base on
information acquired from non measurement techniques like observation.
REFERENCES
Babyegeye E.B.,(1998).Test and measurements .The open university of Tanzania .Dar es
salaam.
Ebel R.L., and Frisbie,D.A (1991).Essentials of Educational Measurement
.New York :Prentice Hall.
Gronlund ,N.E and Linn ,R.L (1990),Measurement and Evaluation in Teaching.N.Y.Macmillan.
Omary ,I.M.(1995).Conceptualizing Quality in Primary Education
.papers in Education and Development,16,25-48.
Thorndike ,R.L,and Hagen,
E.P.,(1991) .Measurements and Evaluation
in psychology and Education :New York .Macmillan.
Tyler,E.E.,(1964).Test and Measurements New Jersey
.Prentice Hall.
Wiersma, W. and Jurs .S.G, (1985).Educational Measurement and Testing
.Allyn and Bacon ,Inc.USA
Social Plugin