Psychological assessment

• Psychometrist


  Tend to use tests merely to obtain data, their task is often perceived as emphasizing the clerical and technical aspects of testing
• Psychometrist


  Data oriented, the end product is often a series of traits or ability descriptions
• Psychological Assessment


  Attempts to evaluate an individual in a problem situation so that the information derived from the assessment can somehow help with the problem
• Psychological Assessment


  Tests are only one method of gathering data, and the test scores are not end products, but merely means of generating hypotheses
• Psychological Assessment


  Places data in a wide perspective, with its focus being problem solving and decision-making
• Intelligence tests


  Appeared to be objective, which would reduce possible interviewer bias
• Test battery


  If a single test could produce accurate descriptions of an ability or trait, administering a series of tests could create a total picture of the person
• Individual differences and trait psychology

  They assume that one of the best ways to describe the differences among individuals is to measure their strengths and weaknesses with respect to various traits
• Psychological assessment has come to include a wide variety of activities beyond merely the administration and interpretation of traditional tests
• One clear change in testing practices has been a relative decrease in the use and status of projective techniques
• Criticisms of projective techniques

  • Overly complex scoring systems
  • Questionable norms
  • Subjectivity of scoring
  • Poor predictive utility
  • Inadequate or even nonexistent validity
• The earliest form of assessment was through clinical interview
• Structured interviews


  • Diagnostic Interview Schedule
  • Structured Clinical Interview for the DSM
  • Renard Diagnostic Interview
• Theoretical orientation


  Clinicians should research the construct that the test is supposed to measure and then examine how the test approaches this construct
• Theoretical orientation


  Clinicians can frequently obtain useful information regarding the construct being measured by carefully studying the individual test items
• Practical considerations

  Tests vary in terms of the level of education (especially reading skills) that examinees must have to understand them adequately
• Practical considerations

  Some tests are too long, which can lead to a loss of rapport with, or extensive frustration on the part of, the examinee
• Practical considerations


  Clinicians have to assess the extent to which they need training to administer and interpret the instrument
• Standardization


  The basis on which individual test scores have meaning relates directly to the similarity between the individual being tested and the sample
• Questions relating to the adequacy of norms

  • Is the standardization group representative of the population on which the examiner would like to use the test?
  • Is the standardization group large enough?
  • Does the test have specialized subgroup norms as well as broad national norms?
• Standardization


  Standardization of administration should refer not only to the instructions, but also to ensuring adequate lighting, quiet, no interruptions, and good rapport
• Reliability


  The reliability of a test refers to its degree of stability, consistency, predictability, and accuracy
• Reliability


  It addresses the extent to which scores obtained by a person are the same if the person is reexamined by the same test on different occasions
• Methods of obtaining reliability

  • Test-retest
  • Alternate forms
  • Split half
  • Interscorer
• Test-retest reliability


  Administering the test and then repeating it on a second occasion, and calculating the reliability coefficient by correlating the scores obtained by the same person on the two different administrations
• Alternate forms


  If the trait is measured several times on the same individual by using parallel forms of the test, the different measurements should produce similar results
• Split half reliability


  The test is given only once, the items are split in half, and the two halves are correlated
• Interscorer reliability


  Two different examiners test the same client using the same test and then determine how close their scores or ratings of the person are
• Standard error of measurement (SEM)

  A statistical index of the amount of error that can be expected for test scores
• Validity


  Assesses what the test is to be accurate about, and whether it measures what it is intended to measure and produces information useful to clinicians
• Methods of establishing validity

  • Content-related
  • Criterion-related
  • Construct-related
• Content validity


  Refers to the representativeness and relevance of the test content to the construct being measured
• Valid test


  Measures what it is intended to measure and produces information useful to clinicians
• A psychological test cannot be said to be valid in any abstract or absolute sense, but more practically, it must be valid in a particular context and for a specific group of people
• A test can be reliable without being valid
• A necessary prerequisite for validity is that the test must have achieved an adequate level of reliability
• Valid test


  Accurately measures the variable it is intended to measure
• Constructing a test


  1. Theoretically evaluate and describe the construct

  2. Develop specific operations (test questions) to measure it
• Main methods of establishing validity

  • Content-related
  • Criterion-related
  • Construct-related
• Content validity


  Representativeness and relevance of the assessment instrument to the construct being measured