Abnormal Psychology PSY404
· Reliability refers to the consistency of measurements, including diagnostic decisions.
· One important form of reliability, known as inter-rater reliability, refers to agreement among
· 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
· 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.
Abnormal Psychology PSY404
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.
· 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
· 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:
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.
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.
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
Example: is the individual laughing or crying, happy or sad, full of expressions or flat without
This estimates the intelligence of the individual. Is the individual of average intelligence, above
average intelligence or below average intelligence?
Abnormal Psychology PSY404
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
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
· 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.
· 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
Abnormal Psychology PSY404
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.
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