QUESTION
How are individual differences measured?
Course: Introduction to Growth and Development
Course code 8610
Level: B.Ed Solved Assignment
ANSWER
MEASUREMENT OF INDIVIDUAL DIFFERENCES
Measurement is the assignment of
a number to an object or event according to a rule. This may represent something
physical, as when you step on the scales and note, with dismay or pleasure the
number that indicates your weight. Or it may be more subtle, as when you take a
vocational aptitude test and receive your score in medical or engineering
aptitude test. To draw a meaningful comparison, measurement must be
meaningful. To have meaning, all measurements must satisfy two basic
criteria: they must be reliable and they must be valid.
(a) Reliability is the indication of the
consistency of measurement, e.g.: If your weight reads 140Ibs, one day, 240
pounds the next day, and 40 pounds the days after, your faith in the precision of
the scale would be secretly shaken. The same is true of psychological tests. Our
measurements must be consistent over repeated tests of measurement. A good test
should yield roughly the same scores over repeated measurements, as long
as that which is being measured does not
change dramatically.
(b) Validity Measurements must also be valid,
validity is an indication of the extent to which a test measures what it is
supposed to measure.
(c) Correlation To give precise statements about reliability and validity, a statistical
technique called correlation may be utilized. It allows scientists to make predictions;
correlation is a statement about the strength of the association between two
(or possibly more) variables. If the correlation between two variables is high, the variables will
tend to be very together, that is, wherever one of the traits is found, chances
are good that the other trait will also be found. If we observe that people
with bland hair usually have blue eyes then we would say that there is a correlation
between the variables of hair color and eye color. This is not to say that having
bland hair causes one to have blue eyes, but it does allow us to predict, whenever
we know that certain individuals have bland hair, that they are also likely to
have blue eyes. As discussed earlier, individuals differ in sensitive,
affective, and psychomotor abilities.
They differ almost in every
respect-personality, attitude, interest, intelligence, and achievement.
Individual differences can be identified and measured through finer
measurement instruments known as psychological tests. A psychological is a
pattern of stimuli, selected and organized to elicit responses that reveal
certain psychological characteristics in the person who makes them. The
following psychological tests can be used by the teacher or psychologists to measure individual differences.
Test of General Intelligence
Sometimes these tests are also
referred to as tests of mental ability, tests of general ability, or tests
of scholastic aptitude, these tests
measure the psychological traits termed “intelligence” which provide the
best possible single clue to the understanding of children’s academic
performances. There are various intelligence tests like the standard-binet
intelligence test (revised), the Wechsler intelligence scale for children, and
various culture-free and culture-fair tests.
Tests of Aptitude
These tests measure the
possibilities of success in future performance. One of the most famous
batteries, which measures children’s different aptitudes, is the “differential
aptitude test battery” which measures the following abilities.
(i) Verbal Reasoning
(ii) Numerical Ability
(iii) Abstract Reasoning
(iv) Space Relations
(v) Mechanical Reasoning
(vi) Clerical Speed and Accuracy
(vii) Language Usage
Interest Inventories
Strong Vocational Interest Blank and Kuder’s Preference Record (Vocational) are some of the interest inventories
that can be used to measure differences among individuals in their interests.
Test of Personality
The MMPI, Bells Adjustment Inventory, and Projective tests
like “The Rorschach Ink Blot test.” Thematic Apperception test and other
questionnaires can be used to measure personality structure and adjustment, and
difficulties of individuals.
Competence-Based Tests
Tests of achievement, mostly
teacher-made types, can be used to measure individual differences in academic
achievement. Practically, these tests as prepared by teachers do not
measure competence in learning various subjects. The competency-based tests
are an improvement over traditional tests and are not difficult to prepare
such tests.
Once the teacher knows the
learning competencies in various school subjects it becomes easy for the
teacher to prepare such tests. It must be noted that scores obtained by a student in any one of the tests
may not be a sure measure of his standing in the group. Scores on tests are
influenced by several factors, internal and external operating at the time
of taking the test. For this purpose scores obtained by one test can be supplemented by scores
obtained from other similar tests.
Multiple-choice tests or Essays
What about multiple-choice tests
or, as many poorly prepared students like to call them, “multiple-guess tests?”
One of the criticisms of the multiple-choice tests is that they reward rote
memorization rather than true understanding. This can certainly happen if the
test is poorly designed, but when thoroughly researched and carefully prepared,
the multiple-choice test can assess a person’s ability to apply concepts to
problem-solving situations.
Rather than break up the units of
knowledge and isolate the pieces, as the critics typically charge, a
well-designed multiple choice test, such as the SAT, demands that the students be
able to understand concepts and bring
facts together. Research evidence clearly shows that the SAT verbal score
shares much in common with IQ, the correlation between them being an extremely
high + 0.80.
What about essay questions? There
is the fear that standardized tests based only on essay questions and writing
samples may hurt learning. Verbally adept but uninformed
students may bluff their way through an essay exam. Similarly, the tactics used
by some students or memorizing or rotting the topics of subjects also affect the learning process. Essay-type exams, however, illuminate the student’s thought process in more detail, as
compared to multiple-choice tests. But for a teacher, with a large class of widely
varying abilities, interests and needs may have to rely on multiple-choice
tests. It not only ensures the reliability of testing but also more importantly permits free time to work with individual students.
Computer Assisted Testing (CAT)
The computer age has led to a
high-tech form of testing called CAT. (Computer-Assisted Testing) Here, the
individual sits at a computer keyboard, and the questions are presented on the
screen. The testing becomes personalized since the testing is interactive with
the computer, in effect custom designing the test to each student’s skill
level. For example, the question may get progressively more difficult until a
level is reached. When a student begins to get the questions wrong, an easier
set of questions suddenly appears. This branching of easier and harder
questions called going “up the ladder” or “down the chute” continues until the
student's true level of competence is reached. The educational testing services of the USA are currently putting both the SAT and GRE (Graduate Record Exam) on a
computer format. Many people believe that CAT is viable, cost-effective, and a
big improvement over paper and pencil testing.
The Portfolio Approach
Another testing technique,
currently gaining in popularity is called the portfolio approach. Just as an
aspiring artist or model carries a portfolio of past work to a prospective
employer, so too does the student who selects examples of his or her best work
over a term or even an entire year of study. It is said that the portfolio
approach places more emphasis on a student’s overall accomplishment than on the
ability merely to score well on a single battery of tests. Typical portfolios
include original poetry, plays, short stories, essays,s, and art projects. Even in
math, a student might produce a series of fractions, showing their relationships
to decimals, or an arrangement of dice to illustrate probabilities, or even
present an essay on the life of the Prophet “Muhammad” (P.B.U.H).
At the end of the year, the
student hands over the portfolios to the teacher for evaluation. Teachers of
the new Millennium should be made aware of this approach and should be given
workshop preparation in learning this technique. The portfolio method can also
be used to evaluate teachers, students, and the curriculum itself. A portfolio
that includes, for example, “samples of student’s teacher developed plans and
materials, videotaped teaching episodes, and other teacher’s reflections on his
or her own teaching can provide direct evidence of what a teacher knows and can
do.
Whether the portfolio approach
proves to be as valuable as it promises is still in question, but there is no
doubt that new testing methods will be employed as educational psychology operates
in the 21st century. New testing procedures are on the horizon, procedures intended
to bridge the gap between cognitive psychology and psychometric methods.
Grade Equivalent Scores
Grade equivalent scores are
based on relating a given student’s
score on a test to the average scores found for other students in a particular
grade, at the same time of year, and of roughly the same age. For example,
assume that in September, a large, representative sample of their graders (III
class, students) of the morning group, produce an average score of 30 on a
certain arithmetic test. If a given student is then tested and receives a
score of 30, that child would be assigned a grade-equivalent score of 3.0 if the child did somewhat better than that and had a score of say 3.4, it would
indicate a performance equal to a third-grade student in the fourth month
(December) of the school year. Grade equivalent scores are typically reported
in tenths of a year so a score of 5.9 refers to the ninth month (June) of
the fifth grade, and a score of 0.0 to the first day of Kindergarten. Thus, the
scores range from 0.0 (or sometimes ko) through 12.9, representing the thirteen
years of school from Kindergarten through grade 12. The first of September is
given on the score as 0, whereas the end of September is 0.1, the end of October
is 0.2, and on until the end of June is 0.9.
Curriculum Testing
Virtually any curriculum that is
more than five years old requires a thorough evaluation, this is most obvious
in fields such as science but should be
done in all areas. This type of testing answers the following:
(a) To
what degree have the curriculum’s goals been reached?
(b) Is the curriculum content appropriate given the mission’s objectives.
(c) Has the instruction been truly based on the
curriculum.
(d) Has the assessment measured the taught
curriculum or planned.
