Unit 2: Types of Psychological Tests

1. Intelligence Tests

Intelligence tests are psychological instruments designed to measure a person’s cognitive capacities and potential for learning. They assess global functioning, including problem-solving, reasoning, memory, and verbal ability.

A. Classification Based on Administration

1. Individual Tests

These tests are administered to one person at a time by a trained examiner.

• Characteristics:
  • Requires a highly trained examiner (rapport building is crucial).
  • Allows for qualitative observation (e.g., observing anxiety, problem-solving strategies).
  • Adaptive: The examiner can adjust the starting point based on the test-taker's ability.
  • Time-consuming and expensive.
• Examples:
  • Stanford-Binet Intelligence Scale: The modern version assesses fluid reasoning, knowledge, quantitative reasoning, visual-spatial processing, and working memory.
  • Wechsler Adult Intelligence Scale (WAIS): The most widely used adult intelligence test. It yields a Full-Scale IQ as well as index scores (Verbal Comprehension, Perceptual Reasoning, Working Memory, and Processing Speed).

2. Group Tests

These tests can be administered to a large number of people simultaneously.

• Characteristics:
  • Efficient and cost-effective (mass testing in schools, military, industry).
  • Simplified instructions and scoring (often multiple-choice).
  • Objective scoring reduces examiner bias.
  • Lack of opportunity to establish rapport or observe anxiety/motivation levels.
• Examples:
  • Army Alpha and Beta: Developed during WWI to assign recruits; Alpha was for literates, Beta for illiterates.
  • Otis-Lennon School Ability Test (OLSAT): Widely used in school settings to screen for gifted programs.

B. Classification Based on Content (Items)

1. Verbal Tests

These tests rely heavily on language usage, reading, and vocabulary.

• Nature: Items involve synonyms, antonyms, arithmetic reasoning, and general knowledge.
• Target Population: Literate individuals with command over the language of the test.
• Limitation: They are culturally loaded; performance depends on educational background and linguistic exposure.
• Example: The Verbal Comprehension Index of the WAIS.

2. Non-Verbal (Performance) Tests

These tests minimize the use of language.

• Nature: Items involve manipulating objects, assembling blocks, completing patterns, or tracing mazes.
• Target Population: Can be used with illiterates, young children, or individuals with speech/language impairments.
• Example: Kohs Block Design Test (reproducing patterns using colored blocks).

3. Culture-Fair / Culture-Reduced Tests

A subset of non-verbal tests designed to be independent of a specific culture's knowledge.

• Raven’s Progressive Matrices (RPM): A strictly visual test where the subject must identify the missing piece of a larger pattern. It measures abstract reasoning and fluid intelligence () without relying on language or learned facts.

2. Personality Tests

Personality tests measure emotional, motivational, interpersonal, and attitudinal characteristics, as distinguished from abilities.

A. Objective Tests (Self-Report Inventories)

Objective tests are structured assessments where the subject answers specific questions (Yes/No, True/False, Likert scales).

• Characteristics:
  • Standardization: Administration and scoring are fixed.
  • Objectivity: Scoring requires no judgment from the examiner.
  • Validity Scales: Many contain built-in mechanisms to detect lying, social desirability, or random answering.
• Key Examples:
  • MMPI (Minnesota Multiphasic Personality Inventory): Used primarily for clinical diagnosis. It assesses psychopathology (e.g., depression, hysteria, schizophrenia) using empirical criterion keying.
  • NEO-PI-R (NEO Personality Inventory): Based on the Big Five factor model (Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism). Used mostly with normal populations.
  • 16PF (Sixteen Personality Factor Questionnaire): Developed by Raymond Cattell using factor analysis to identify source traits.
• Limitations:
  • Social Desirability Bias: Subjects may fake "good."
  • Acquiescence: Tendency to agree with items regardless of content.

B. Projective Tests

Projective tests present the subject with ambiguous stimuli and ask them to interpret them. The theory is based on the Projective Hypothesis: individuals project their own unconscious needs, conflicts, and drives onto the ambiguous stimuli.

• Characteristics:
  • Unstructured stimuli (inkblots, vague pictures).
  • Indirect method (the subject does not know what is being measured).
  • Heavily reliant on psychoanalytic theory.
• Key Examples:
  • Rorschach Inkblot Test: Consists of 10 bilaterally symmetrical inkblots. Scoring is complex (Exner system) and looks at location (part of blot used), determinants (shape, color, shading), and content.
  • Thematic Apperception Test (TAT): Developed by Murray and Morgan. Subjects view ambiguous scenes involving people and must tell a story (past, present, future). It reveals needs (e.g., Need for Achievement, Need for Power) and press (environmental forces).
  • Sentence Completion Tests: (e.g., Rotter Incomplete Sentence Blank). The subject finishes a stem like "My father..."
• Limitations:
  • Low reliability (different scorers may interpret responses differently).
  • Questionable validity compared to objective tests.

3. Aptitude Tests

Aptitude refers to the potential to acquire a specific skill or knowledge in the future given training. While intelligence is global capacity, aptitude is specific potential.

A. General Aptitude Tests (Multiple Aptitude Batteries)

These provide a profile of scores across several distinct aptitudes rather than a single IQ score. They are often used for educational and vocational counseling.

• Differential Aptitude Test (DAT):
  • One of the most widely used batteries for high school students.
  • Sub-tests include: Verbal Reasoning, Numerical Ability, Abstract Reasoning, Clerical Speed and Accuracy, Mechanical Reasoning, Space Relations, Spelling, and Language Usage.
• General Aptitude Test Battery (GATB):
  • Developed by the US Employment Service.
  • Measures 9 aptitudes including General Learning Ability (G), Verbal (V), Numerical (N), Spatial (S), Form Perception (P), Clerical Perception (Q), Motor Coordination (K), Finger Dexterity (F), and Manual Dexterity (M).

B. Specific Aptitude Tests

These are designed to measure potential in one specific area.

1. Mechanical Aptitude: Measures understanding of mechanical principles and spatial visualization.
   • Example: Bennett Mechanical Comprehension Test. Used for engineering and technical trade selection.
2. Clerical Aptitude: Measures perceptual speed and accuracy (checking numbers/names quickly).
   • Example: Minnesota Clerical Test. Used for bank tellers and administrative assistants.
3. Artistic/Musical Aptitude: Measures sensitivity to pitch, rhythm, and aesthetic judgment.
   • Example: Seashore Measures of Musical Talents.
4. Professional Aptitude: Used for entrance into professional schools.
   • Examples: LSAT (Law), MCAT (Medical).

4. Attitude Scales

Attitudes are evaluative statements (favorable or unfavorable) related to objects, people, or events. Attitude scales quantify these constructs.

A. Thurstone Scale (Method of Equal-Appearing Intervals)

• Construction:
  1. A large pool of statements regarding a topic is generated.
  2. A panel of "judges" sorts these statements into 11 piles ranging from "Extremely Unfavorable" to "Extremely Favorable."
  3. Statements with high agreement among judges are selected.
  4. Each item is assigned a scale value (median of judges' placements).
• Scoring: The respondent checks the statements they agree with. The score is the average/median scale value of the agreed items.
• Pros/Cons: highly precise but very difficult and time-consuming to construct.

B. Likert Scale (Method of Summated Ratings)

• Construction:
  • Respondents indicate their level of agreement with a statement on a multipoint scale (usually 5 or 7 points).
  • Typical anchors: Strongly Disagree (1) – Disagree (2) – Neutral (3) – Agree (4) – Strongly Agree (5).
• Scoring: The values are summed to give a total attitude score.
• Pros/Cons: Easiest to construct and most widely used in social science research.

C. Guttman Scale (Cumulative Scaling)

• Concept: Items are arranged in a hierarchy of difficulty or intensity.
• Logic: If a person agrees with a strong statement, they will also agree with all weaker statements preceding it.
• Example:
  1. "I would let an immigrant live in my country." (Least intense)
  2. "I would let an immigrant live in my neighborhood."
  3. "I would let an immigrant marry my child." (Most intense)
• Utility: Useful for checking if an attitude is unidimensional.

D. Semantic Differential Scale (Osgood)

• Concept: Measures the connotative meaning of an object.
• Format: The subject rates a concept (e.g., "Democracy") on a series of 7-point bipolar adjective scales.
• Dimensions:
  1. Evaluation: Good–Bad (Most dominant dimension).
  2. Potency: Strong–Weak.
  3. Activity: Active–Passive.

Summary Table: Types of Tests