|
|||||
Abnormal
Psychology PSY404
VU
LESSON
17
EVALUATING
SYSTEMS
Reliability
·
Reliability
refers to the consistency of
measurements, including diagnostic
decisions.
·
One
important form of reliability,
known as inter-rater reliability, refers
to agreement among
clinicians.
Validity
·
Validity
refers to the meaning or importance of a
measurement--in this case, a diagnostic
decision.
·
Validity
is, in a sense, an index of the
success that has been
achieved in understanding the nature
of
a
disorder.
·
Etiological
validity is concerned with
factors that contribute to the
onset of the disorder.
·
Concurrent
validity is concerned with the
present time and with correlations
between the disorder
and
other symptoms, circumstances,
and test procedures.
·
Predictive
validity
is
concerned with the future
and with the stability of the
problem over time.
·
Each
time the DSM-IV-TR is revised, new
categories are added and
old categories are
dropped,
presumably
because they are not
sufficiently useful.
Problems
and Limitations of the DSM-IV-TR
System
DSM-IV-TR
does not classify clinical
problems into syndromes in the
simplest and most beneficial
way.
·
One of the
important issues involves
comorbidity,
which
is defined as the simultaneous
appearance
of two or more disorders in the
same person.
·
Co
morbidity rates are very
high for mental disorders as
they are defined in the DSM
system.
Basic
Issues in Assessment
Purposes
of Clinical Assessment
·
Psychological
assessment is the
process of collecting and interpreting
information that will
be
used
to understand another person.
·
Three primary
goals guide most assessment
procedures: making predictions, planning
treatments,
and
evaluating treatments.
·
Different
assessment procedures are
likely to be employed for
different purposes.
Assumptions
about Consistency of Behavior
·
Psychologists
must be concerned about the
consistency of behavior across time
and situations.
·
They want to
know if they can generalize
about the
person's behavior in the natural
environment
on
the basis of the samples of behavior
that are obtained in their
assessment.
·
Psychologists
typically seek out more
than one source of
information when conducting a
formal
assessment.(
observation, interview, and psychological
tests )
·
Because
we are trying to compose a broad,
integrated picture of the person's adjustment, we
must
collect
information from several
sources and then attempt to integrate
these data.
·
One
way of evaluating the possible meaning or
importance of this information is to consider
the
consistency
across sources.
Evaluating
the Usefulness of Assessment
Procedures
·
In the
case of assessment procedures,
reliability can refer to various
types of consistency.
·
For
example, the consistency of measurements
over time is known as testretest
reliability.
·
The
internal consistency of items
within a test is known as
split-half
reliability.
·
The
validity of an assessment procedure
refers to its meaning or
importance.
77
Abnormal
Psychology PSY404
VU
·
Is
the person's score on this test or
procedure actually a reflection of the
trait or ability that the
test
was
designed to measure?
·
And
does the score tell us
anything useful about the
person's behavior in other
situations?
·
In
general, the more consistent the
information provided by different
assessment procedures, the
more
valid each procedure is
considered to be. Interviews,
observational procedures, and
personality
tests must be carefully
evaluated.
·
The
most useful assessment
procedures are likely to vary
from one problem to the
next.
·
Assessment
procedures that are useful
in evaluating the effectiveness of a drug treatment
program
for
hospitalized depressed patients may be
quite different from those
used to predict the need
for
medication
among hyperactive schoolchildren.
Interviews
·
The
clinical interview is the most commonly
used procedure in psychological
assessment.
·
Most
of the categories that are
defined in DSM-IV-TR are
based on information that
can be
collected
in an interview.
·
Interviews
provide an opportunity to ask people
for their own descriptions
of their problems.
·
Interviews
also allow clinicians to
observe important features of a
person's appearance
and
nonverbal
behavior.
Structured
Interviews
·
Assessment
interviews vary with regard to the amount of
structure that is imposed by the
clinician.
·
Some
are relatively open-ended, or
nondirective.
·
Structured
interviews, in
which the clinician must ask
each patient a specific list
of detailed
questions,
are frequently employed for
collecting information that will be
used to make
diagnostic
decisions
and to rate the extent to which a
person is impaired by psychopathology.
·
Structured
interviews list a series of specific
questions that lead to a
detailed description of the
person's
behavior and
experiences.
·
Structured
interview schedules provide a
systematic framework for the collection
of important
diagnostic
information, but they don't eliminate the
need for an experienced
clinician
The
Mental Status
Examination
The
mental status examination involves
systematic observation of an individual's
behavior. This type of
observation
occurs when one individual
interacts with another.
Mental status examination can be
structured
and
detailed. It covers five
categories:
1.
Appearance
and behavior
This
includes individual's dress,
appearance, posture and
facial expression e.g. an
individual can
be
slow, lazy and lethargic.
Another individual can be
active and agile.
2.
Thought
Process
Clinicians
listen to patient's talk and they get a
good idea of the patient
thought process. Is
his
talk
reality oriented, each idea connected
with one another or is it full of
fantasy, delusions
hallucinations
or is it disjointed speech with no
association of ideas e.g.
schizophrenia.
3.
Mood
and affect
A
mental health clinician focuses on mood
which is the feeling state of the individual
and affect
reflects
the emotion. Is the client and
his talk depressed or in a
hopeless fashion or is it in
optimistic
fashion.
Example:
is the individual laughing or crying, happy or sad,
full of expressions or flat
without
expression.
4.
Intellectual
Function
This
estimates the intelligence of the individual. Is the
individual of average intelligence,
above
average
intelligence or below average
intelligence?
78
Abnormal
Psychology PSY404
VU
5.
Perception
of person, place and
time.
This
refers to, does the
individual know, who he is,
where he is and what date
and what time is
it?
The
mental status examination tells us
how people think, feel and
behave and how these
actions might
contribute
to explain their problems. So actually, we
are doing behavioral assessment of
people. This
behavioral
assessment is done by using direct observation of an
individual's thought, feelings
and behavior
in
situations or context where the
individual is having problems.
Advantages
of the Clinical Interview as an
Assessment Tool
1.
The interviewer can control
the interaction and can
probe further when necessary. By
observing the
patient's
nonverbal behavior, the interviewer
can try to detect areas of
resistance. In that sense,
the
validity
of the information may be
enhanced.
2.
An interview can provide a
lot of information in a short period of
time.
Limitations
of the Clinical Interview as an
Assessment Tool
1.
Some patients may be unable
or unwilling to provide a rational
account of their
problems.
2.
People may be reluctant to admit
experiences that are
embarrassing or frightening.
3.
Subjective factors play an important
role in the interpretation of information
provided in an
interview.
Observational
Procedures
·
Observational
skills play an important part in
most assessment
procedures.
·
Sometimes
the things that we observe confirm the
person's self-report, and at other
times the
person's
overt behavior appears to be at
odds with what he or she
says.
·
Observational
procedures may be either informal or
formal.
·
Informal
observations are primarily
qualitative.
·
The
clinician observes the person's behavior
and the environment in which it
occurs without
attempting
to record the frequency or intensity of
specific responses.
·
Although
observations are often
conducted in the natural environment,
there are times when it
is
useful
to observe the person's behavior in a
situation that the psychologist can
arrange and control.
Rating
Scales
·
A
rating
scale is a
procedure in which the observer is
asked to make judgments that
place the
person
somewhere along a dimension.
·
Ratings
can also be made on the
basis of information collected
during an interview.
·
Rating
scales provide abstract
descriptions of a person's behavior
rather than a specific record
of
exactly
what the person has
done.
These
are assessment tools, which
are used before the treatment to assess
changes in patient's
behavior
after the treatment. Brief psychiatric
rating scales are usually
used and completed by
hospital
staff
to assess an individual on different
constructs related with
physical or psychological
illness.
Behavioral
Coding Systems
·
Rather
than making judgments about where the
person falls on a particular dimension,
behavioral
coding
systems focus
on the frequency of specific behavioral
events.
·
Some
adult clients are able to
make records and keep
track of their own
behavior--a procedure
known
as self-monitoring.
Advantages
of Observational Methods
·
Rating
scales are primarily useful
as an overall index of symptom
severity or functional impairment.
·
Behavioral
coding systems provide detailed
information about the person's
behavior in a particular
situation.
79
Abnormal
Psychology PSY404
VU
Limitations
of Observational Methods
Observational
procedures can be time-consuming
and therefore expensive. Observers
can make errors.
People
may alter their behavior, either
intentionally or unintentionally, when
they know that they are
being
observed--a
phenomenon known as reactivity.
·
Observational
measures tell us only about
the particular situation that was
selected to be observed.
·
There
are some aspects of psychopathology
that cannot be observed by anyone
other than the
person
who has the problem.
80
Table of Contents:
|
|||||