This document discusses assumptions and considerations for psychological testing. It covers the following key points: 1. There is an assumption that psychological traits and states exist and can be measured. Traits are enduring ways people vary, while states are less enduring. 2. Tests aim to predict non-test behavior, but have strengths and weaknesses. Competent examiners understand a test's limitations and appropriateness. 3. Norms provide a reference for interpreting individual scores by comparing performance to a sample group. Good tests are reliable, valid, and have practical administration procedures that benefit society.

1. CHAPTER 4
OF TESTS AND TESTING

2. What is a “good test”?

3. ASSUMPTION 1: Psychological Traits
and States Exist
Trait has been defined as “any
distinguishable, relatively enduring way
in which one individual varies from
another” (Guilford, 1959, p. 6).
States distinguish one person from
another but are relatively less enduring
(Chaplin et al., 1988).

4. Psychological trait covers a wide range of
possible characteristics.
 Construct – an informed, scientific concept
developed or constructed to describe or explain
behaviour.
 Overt Behaviour – refers to an observable
action or the product of an observable action,
including test- or assessment-related
responses.
The definitions of traits and states we are using
also refer to a way in which one individual
varies from another.

5. ASSUMPTION 2: Psychological Traits
and States Can Be Qualified and
Measured
 Having acknowledge that psychological
traits and states do exist, the specific
traits and states to be measured and
quantified need to be carefully defined.

6. ASSUMPTION 3: Test-related
Behavior Predicts Non-Test-
Related Behavior
 Patterns of answers to true-false questions
on one widely used test of personality are
used in decision making regarding mental
disorders.
 The task in some tests mimic the actual
behaviors that the test users is attempting
to understand.
 The obtained sample of behavior is
typically used to make predictions about
future behavior.

7. ASSUMPTION 4: Tests and Other
Measurement techniques Have
Strengths and Weaknesses
Competent test users understand a great deal
about the tests they use.
 They understand, among other things, how a
test was developed, the circumstances under
which it is appropriate to administer the test.
 Competent test users understand and appreciate
the limitations of the tests they use as well as
how those limitations might be compensated for
data from other sources.

8. ASSUMPTION 5: Various Sources of
Error are Part of the Assessment
Process
• Error traditionally refers to something more
than expected; it is actually a component of
the measurement process. More specifically,
error refers to a long-standing assumption
that factors other than what a test attempts
to measure will influence performance on
the test.

9. Error Variance
- is a component of a test score attribute
to sources other than the trait or ability
measured.
Potential Sources of Error Variance
1. Assessee
2. Assessors
3. Measuring Instruments
Classical or true score theory of measurement, an
assumption is made that each testtaker has a true
score on test that would be obtained but a random
action of measurement error.

10. ASSUMPTION 6: Testing and
Assessment Can Be Conducted in a
Fair and Unbiased Manner
Decades of court challenges to various tests and
testing programs have sensitized test
developers and users to the societal demand
for fair tests used in a fair manner.
Today, all major test publishers strive to develop
instruments that are fair when used in strict
accordance with guidelines in the test manual.
 Test tools are just like other tools, they can be used
properly or improperly.

11. ASSUMPTION 7: Testing and
Assessment Benefit Society
 Considering the many critical decisions that are based
on testing and assessment procedures, we can readily
appreciate the need for test, especially good tests.

12. What is a “good test”?
Psychometric soundness of tests,
1. Reliability
2. Validity

13. Reliability
- involves the consistency of the measuring
tools: the precision with which the test
measures and the extent to which error is
present in measurements.
In theory, the perfectly reliable measuring tool
consistently measure in the same way.
Validity
- a test is considered valid for a particular
purpose if it does, in fact, measure what it
purports to measure.

14. Other Considerations
A good test is one that trained examiners can
administer, score, and interpret with a
minimum of difficulty. A good test is useful
test, one that yields actionable results that will
ultimately benefit individual test takers or
society at large.

15. Norms
Norm-referenced testing and assessment
Method of evaluation and a way of deriving
meaning from test scores by evaluating an
individual test taker’s score and comparing it to
scores of a group test takers.
Individual test score is understood relative to
other scores on the same test.
Norms – test performance data of a particular
group of test takers that are designed for use
as reference when evaluating or interpreting
individual test scores.

16. Normative Sample – group of people whose
performance on a particular test is analyzed for
reference in evaluating the performance of
individual test takers.
Norming – process of deriving norms.
Race Norming – is the practice of adjusting test
scores to account for the race or ethnicity of the
test-taker.
User Norms/Program Norms – “consist of
descriptive statistics based on group of test takers
in given period of time rather than norms obtained
by formal sampling methods” (Nelson, 1994, p.
283).

17. Sampling to Develop Norms
Standardization/Test Standardization
- process of administering a test to a
representative sample of test takers for the
purpose of establishing norms.
Sampling
- process of selecting the portion of the
universe deemed to be representatives of the
whole population.
Sample of a population
- portion of the universe of people deemed to
be representative of the whole population.

18. Stratified Sampling
- process of developing a sample based on specific
subgroups of a population.
Stratified-random Sampling
- process of developing a sample based on specific
subgroups of a population in which every member
has the same chance of being included in the
sample.
Purposive Sample
- arbitrarily select some sample because it is
believed to be representative of the population.
Incidental Sample/Convenience Sample
- involves the sample being drawn from that part
of the population that is close to hand.

19. Types of Norms
1. Percentile Norms – are the raw data from a
test’s standardization sample converted to
percentile form.
>Percentage Correct – refers to the
distribution of raw scores.
2. Age Norms ( Age-equivalent scores) – indicate
the average performance of different sample
test takers who were at various ages at the
time test was admitted.
3. Grade Norms – designed to indicate the
average test performance of test takers in a
given school grade.

20. 4. National Norms – derived from a normative
sample that was national representative of the
population at the time the norming study was
conducted.
5. National Anchor Norms – provide some stability
to test scores by anchoring them to other test
scores.
6. Subgroup Norms
7. Local Norms – typically developed by test
users themselves, provide normative
information with respect to the local
population’s performance on some test.

21. Normative sample
- is that group of people whose performance on
a particular test is analyzed for reference in
evaluating the performance of individual test
takers.
Normative Data
- provide a standard with which the results of
measurement can be compared.

22. Norm-Referenced versus Criterion-
Referenced Evaluation
Norm-Referenced Testing and Assessment
- is a method of evaluation and a way of
deriving meaning from test scores by evaluating
an individual test taker’s score and comparing
it to scores of a group of test takes.
Criterion-Referenced Testing and Assessment
- may be defined as a method of evaluation and
a way of deriving meaning from test scores by
evaluating an individual’s score with reference
to a set standard.

23. Sampling to Develop Norms
1. Stratified sampling – help prevent sampling bias
2. Stratified-random sampling – every member of
the population had the same chance of being
included in the sample
3. Purposive sample – selects some samples to be
representative of the population
4. Incidental/convenience sample – important
distinction between what is ideal and what is
practical in sampling

24. Standardization or test standardization
- The process of administering a test to a
representative sample of test takers for the
purpose of establishing norms.
Standard error of the difference
- A statistic used to estimate how large a
difference between two scores should be
before the difference is considered
statistically significant

25. Central to psychological testing and assessment
are inferences (deduced conclusions) about how
some things (such as traits, abilities, or
interests) are related to other things (such as
behavior).
Correlation – is an expression of the degree and
direction of correspondence between two things
Coefficient of correlation (r) – expresses a
linear relationship between two (and only two)
variables, usually continuous in nature.

26. • Positively (or directly) correlated
- If two variables simultaneously increase or
simultaneously decrease
• Negative (or inverse) correlation
- Occurs when one variable increases while the
other variable decreases
• If a correlation is zero, then absolutely no
relationship exists between the two variables.

27. Techniques to measure correlation
1. Pearson r – most widely used index of
correlation (Karl Pearson)
- relationship between the variables is linear and
when the two variables being correlated are
continuous
- coefficient of determination is an indication of
how much variance is shared by the X- and the Y-
variables

28. 2. Spearman’s rho – called a rank-order
correlation coefficient, a rank-difference
correlation coefficient (Charles Spearman)
- frequently used when the sample size is
small and especially when both sets of
measurements are in ordinal (or rank-order)
form.

29. Graphic Representations of Correlation
• Scatterplot – is a simple graphing of the
coordinate points for values of the X -
variable and the Y –variable
- Scatterplots are useful in revealing the
presence of curvilinearity in a relationship
- Curvilinearity in this context refers to an
“eyeball gauge” of how curved a graph is
- Outlier is an extremely atypical point located
at a relatively long distance from the rest of
the coordinate points in a scatterplot.

30. 3. Regression – defined broadly as the analysis of
relationships among variables for the purpose of
understanding how one variable may predict another
a. Simple regression involves one independent
variable (X), typically referred to as the
predictor variable, and one dependent variable
(Y), typically referred to as the outcome
variable.
b. Multiple regression – the use of more than
one score to predict
- The multiple regression equation takes into
account the intercorrelations among all the
variables involved

31. Inference from Measurement
Correlation, regression, and multiple regression
are all statistical tools used to help ensure that
predictions or inferences drawn from test data
1. Meta-analysis – refers to a family of
techniques used to statistically combine
information across studies to produce single
estimates of the statistics being studied