An assessment instrument is a standardized or non-standardized tool used to collect valid and reliable information about an individual’s skills, characteristics, or behaviors, with the purpose of guiding diagnosis, intervention, and follow-up.

Every assessment instrument must meet the following characteristics:

Validity: measures what it is intended to measure.

Reliability: produces consistent and stable results.

Standardization: includes uniform norms and procedures for administration.

Relevance: appropriate for the purpose and population.

Objectivity: minimizes evaluator influence on the results.

By type:

Standardized tests

Checklists

Observation tools

Developmental scales

Interviews

By area:

Cognitive

Motor

Language

Socio-emotional

Example 1:

Name: Bayley Scales of Infant Development (BSID)

Area assessed: Cognitive, motor, and language

Age group: 1 to 42 months

Description: Standardized scale that measures cognitive, motor, and language development in young children.

Example of use: To identify developmental delays and design early stimulation programs.

Example 2:

Name: Ages and Stages Questionnaires (ASQ)

Area assessed: General development (motor, communication, socio-emotional)

Age group: 1 month to 5 years

Description: Screening questionnaire completed by parents to detect risks in different areas of child development.

Example of use: Helps psychologists and educators identify areas that need early intervention.

Bayley, N. (2006). Bayley Scales of Infant and Toddler Development (3rd ed.). San Antonio, TX: Harcourt Assessment.

Squires, J., & Bricker, D. (2009). Ages & Stages Questionnaires®, Third Edition (ASQ-3). Baltimore: Paul H. Brookes Publishing Co.

American Psychological Association (2020). Standards for Educational and Psychological Testing. Washington, DC: APA.