Chapter 4 Flashcards
psychological assessment
a systematic gathering and evaluation of information pertaining to an individual with suspected
abnormal behaviour. This assessment can be carried out
with a wide variety of techniques to appraise social, psychological, and/or biological factors
- a diagnosis is only as good as its assessment
- A good assessment tool depends on two things: an accurate ability to measure some aspect of the person being assessed, and knowledge of how people in general fare on
such a measure, for the purposes of comparison
Test-retest reliability
refers to the degree to which a
test yields the same results when it is given more than once to the same person.
alternate-form reliability
One obvious problem (with test-retest reliability) is that a person may improve on a test the second time around because of practice with the procedures or familiarity with the questions. To circumvent this
problem, behavioural scientists often attempt to ascertain a test’s alternate-form reliability. To do this, the test designers prepare two forms of the same test—that is, they decide
what construct they want their test to measure, develop questions (or items) that would test that construct, and then word those questions in a slightly different way to create a
comparable second version of the test that correlates highly
with the first test.
Internal consistency
refers to the degree of reliability
within a test. That is, to what extent do different parts of the same test yield the same results?
split-half reliability
comparing responses on odd-numbered test items with
responses on even-numbered test items. If the scores for
these responses are highly correlated, then the test has high
split-half reliability
coefficient alpha
averaging the intercorrelations of all items on a given test. The higher
the coefficient alpha, the higher the internal consistency of the test.
Face validity
the user of a test believes that
the items on that test resemble the characteristics associated
with the concept being tested.
Content validity
requires that a test’s content include a representative sample of all
behaviours thought to be related to the construct (i.e., the
concept or entity) that the test is designed to measure.
criterion validity
arises because some
qualities are easier to recognize than to define completely.
- Suppose you wanted to know whether a calculator was working properly; you could input a problem to which you already know the answer: say, “6 × 5.” If the calculator gives an answer of 368, you know it is not a valid instrument.
- Now suppose you wanted to develop a test for artistic ability. You
design an instrument that asks many questions about creative behaviour and activities. You then give the test to a large group of well-known and highly regarded artists and to
a control group of people not identified as artistic. If the artists’ test scores are much higher than the non-artists’ scores, your test has good criterion validity
Construct validity
refers to the importance of a test
within a specific theoretical framework and can only be
understood in the context of that framework. This type of
validity is especially useful when the construct to be measured is abstract, such as self-esteem
clinical approach
there is no substitute for the clinician’s experience and personal judgment. They prefer to draw on all available data in their own manner;
they are guided by intuition honed with professional experience rather than by formal rules
actuarial approach
a more objective standard is needed—something primarily based in empirical data. They rely exclusively on statistical procedures, empirical methods, and formal rules in evaluating data.
computerized axial tomography (CAT)
or CT scan. In this procedure, a narrow band of X-rays is projected through
the head and onto scintillation crystals, which are much more sensitive than X-ray film. The X-ray source and detector then rotate very slightly and project another image; to complete the scan, the source rotates a total of 180 degrees, producing a number of images at predetermined angles.
magnetic resonance
imaging (MRI)
- reveal both the structure and the functioning of the brain
- A strong homogeneous magnetic field is produced around the patient’s head. This field causes atoms with odd atomic weights (especially hydrogen) to align their electrons parallel to the direction of the field.
- Brief pulses of radio waves are subsequently introduced, causing these
electrons to move in a characteristic gyroscopic manner. When the radio waves are turned off, the electrons return to their original configuration and, in doing so, emit radio waves of their own at a characteristic frequency, which can then be detected outside a patient’s head. - By adding a small magnetic gradient to the field, the frequency of radio wave
transmission by atoms within the brain is altered to correlate with the gradient, allowing scientists to determine the location of the radio source. The information gathered is then
integrated into a computer-generated image of the brain
Positron emission tomography (PET)
- a combination of computerized tomography and radioisotope imaging.
- the radiation is generated by injected or inhaled radioisotopes—that
is, common elements or substances that have had the atom altered to be radioactive - As the substance is used in brain activity, radiation is given off and
detected by the PET equipment. This process allows the scientist to measure a variety of biological activities as the processes occur in the living brain.
clinical interviews
Practitioners ask about many
aspects of the individual’s life: medical history, psychiatric history, age, marital status, family, education, and lifestyle, as well as the reason the person is seeking consultation.
unstructured interviews
- open-ended, allowing the
interviewer to pursue a specific line of questioning or to follow the patients’ lead. - it is relatively easy to avoid a sensitive topic until a patient is more at ease. Thus, the main advantage
of unstructured interviews is that they facilitate rapport, mutual trust, and respect between clinician and patient. - criticism: poor reliability and validity. The clinician’s own theoretical orientation and personality greatly influence the type of information sought
structured interviews
- By increasing the standardization of a diagnostic interview, and requiring that
each question be read aloud verbatim, researchers are able to obtain the information they need without having to rely on the judgments of individual lay interviewers - criticism: tend to jeapordize rapport
semi-structured interviews
The questions are guided, however, by an outline that lists certain dimensions
of the patient’s functioning that need to be covered. The most frequently used semi-structured interview in psychiatric settings is the mental status examination which screens for patients’ emotional, intellectual, and neurological functioning. It is used in formal diagnosis or to plan treatment.
- designed to look for specific problems
rating scales
- keep observer inferences to a minimum. The most useful rating scales are those that enable a rater to indicate not only the presence or absence of a trait or behaviour but also its prominence or degree
personality assessments
personality assessments usually describe various characteristics that make up an individual’s unique personality. A wealth of tests, questionnaires, and rating scales are
available that offer shortcuts to understanding an individual
and to predicting behaviour.
Projective tests
The theory behind a projective test is that a person presented with an ambiguous stimulus will project onto that stimulus his or her unconscious motives, needs, drives, feelings, defences, and personality characteristics. Thus, the test reveals information that the person cannot or will not report directly
Rorschach Inkblot Test
He noticed that people saw different things in the same inkblot, and he believed that their “percepts” reflected
their personality
Exner system
The Exner system was developed in an
attempt to increase reliability and validity by standardizing the scoring of responses
Thematic Apperception Test
was developed by psychologists Henry Murray and Christiana Morgan
The TAT consists of drawings on cards depicting ambiguous social interactions (see Figure 4.6). Individuals are asked
to construct stories about the cards. Respondents are asked what they believe is happening in the scenes, what led up to these actions, what thoughts and feelings the character is
experiencing, what happens next, and so on. Psychodynamically oriented clinicians assume that respondents identify with the protagonist or victims in their stories, and project their psychological needs and conflicts into the events they apperceive.
Minnesota Multiphasic Personality Inventory (MMPI)
questions grouped to form
10 content scales plus additional scales to detect sources of invalidity such as carelessness, defensiveness, or evasion (see Table 4.3). Each item is a statement; the respondent is asked to check “True,” “False,” or “Cannot Say.” Many items appear to have little face validity—it is difficult to infer what the question is supposed to measure.
