📘 NCE Study Guide: Assessment and Testing

🔑 Key Definitions

• Measurement: Assigning numerical values to characteristics according to specific rules.
  Example: Using a Likert scale to measure anxiety levels.

• Assessment: A broader term that encompasses the process of collecting information to make decisions about individuals. It includes tests, interviews, observations, and more.

• Appraisal: The process of evaluating an individual’s performance or behavior using various tools (e.g., tests, observations).

• Interpretation: Making sense of the assessment results to draw conclusions or make decisions.

📊 Statistical Concepts in Assessment

Measures of Central Tendency

• Mean: The average score.

• Median: The middle score.

• Mode: The most frequent score.

Example: If scores are 3, 4, 4, 6, 8 — mean = 5, median = 4, mode = 4.

Measures of Variability

• Range: Difference between highest and lowest scores.

• Variance: Average squared deviation from the mean.

• Standard Deviation (SD): Square root of the variance; shows how spread out scores are.

Skewness (SKUs)

• Positive Skew: Tail is to the right; most scores are low.
  Example: A very hard test where most students scored low.

• Negative Skew: Tail is to the left; most scores are high.
  Example: A very easy test where most students scored high.

Normal Curve

• Symmetrical bell-shaped curve.

• 68-95-99.7 Rule: About 68% of scores fall within ±1 SD, 95% within ±2 SD, and 99.7% within ±3 SD of the mean.

Standardized Scores

• Z-scores: Mean = 0, SD = 1

• T-scores: Mean = 50, SD = 10

• Stanines: Range from 1 to 9; mean = 5, SD = ~2

Percentiles

• Represent the percentage of scores below a particular score.
  Example: A percentile rank of 85 means the person scored better than 85% of the test takers.

Grade & Age-Equivalent Scores

• Grade Equivalent: Indicates the grade level of performance.
  Example: 5.4 means performance similar to a 5th grader in the 4th month.

• Age Equivalent: Indicates the age level of performance.

⚠️ These can be misleading and should be interpreted cautiously.

🔗 Correlation and Reliability

Correlation Coefficients (r)

• Range from -1.00 to +1.00

• Closer to ±1.00 = stronger relationship

• Positive = both variables increase or decrease together

• Negative = one increases, the other decreases

Reliability

Refers to consistency or stability of scores.

Types:

• Test-Retest Reliability: Same test given twice; looks at consistency over time.

• Inter-Rater Reliability: Consistency between different evaluators.

• Parallel/Alternate Forms Reliability: Different versions of the same test yield similar results.

• Internal Consistency:

  • Split-Half: Compare two halves of the same test.

  • Cronbach’s Alpha: Measures internal consistency for items on a scale.

True and Error Variance

• True Score: The actual score that reflects the trait being measured.

• Error Variance: Random errors that affect the score (e.g., fatigue, mood, environment).

Standard Error of Measurement (SEM)

• Estimate of how repeated measures of a person on the same instrument tend to be distributed around their “true” score.

• Smaller SEM = more reliable score.

✅ Validity

Validity refers to how well a test measures what it claims to measure.

Types:

• Content Validity: Does it measure the full range of the concept?
  Example: A math test that includes all key topics from the curriculum.

• Construct Validity: Does it truly measure the theoretical construct?

  • Convergent Validity: Correlates with similar constructs.

  • Discriminant Validity: Does not correlate with unrelated constructs.

• Criterion-Related Validity:

  • Concurrent: Correlates with other measures taken at the same time.

  • Predictive: Correlates with future outcomes.
    Example: SAT scores predicting college GPA.

Note: A test can be reliable (consistent) without being valid (accurate), but it cannot be valid if it is not reliable.

🧪 Types of Assessments

• Achievement Tests: What has already been learned (e.g., academic tests).

• Aptitude Tests: Potential to learn (e.g., SAT, GRE)

• Intelligence Tests: General mental ability (e.g., WAIS, WISC).

• Personality Tests:

  • Objective: MMPI-2, NEO-PI-R

  • Projective: Rorschach Inkblot, TAT

• Interest Inventories: Preferences and interests (e.g., Strong Interest Inventory).

• Neuropsychological Tests: Assess brain function (e.g., Bender Visual Motor Gestalt).

🛠️ Assessment Techniques

• Standardized vs. Non-Standardized:

  • Standardized: Normed, consistent procedures.

  • Non-Standardized: Informal, flexible, individualized.

• Inventories: Often self-report tools (e.g., Beck Depression Inventory).

• Observations: Behavior in naturalistic or controlled settings.

• Case History: Background info including medical, educational, social.

• Rating Scales: Numerical or descriptive judgments (e.g., Likert scale).

• Interviews: Structured or unstructured.

• Sociometry: Measures social relationships within a group (e.g., peer nominations).

• Social Desirability Bias: Tendency to respond in a socially acceptable manner.

📈 Interpreting Test Scores

• Raw Score: The original score obtained.

• Standard Scores: Converted scores allowing comparison.

• Percentile Rank: See earlier.

• Age/Grade Equivalents: See earlier.

• Confidence Interval: Likely range where true score lies (based on SEM).

💻 Computer-Based Assessments

• Efficient and increasingly common.

• Examples: Online IQ tests, computerized adaptive testing (e.g., GRE).

• Ethical concerns include privacy, accessibility, and validity of online platforms.

⚖️ Ethical Issues in Testing

• Informed consent

• Confidentiality

• Cultural fairness and bias

• Appropriate use and interpretation of scores

• Qualifications for test administration

• Test security

ACA Code of Ethics (2014) and AERA, APA, NCME Standards (2014) guide ethical testing practices.

📚 Assessment Resources

• Mental Measurements Yearbook (MMY): Reviews and info on thousands of tests.

• Tests in Print: Comprehensive list of commercially available tests.

• Buros Center for Testing: Online access to test reviews.

• ETS Test Collection: Educational Testing Service database.