The Wechsler Intelligence Scale for Children – Fifth Edition (WISC-V) is a clinical and psychometric tool that is individually administered to children between the ages of 6 and 16 years old for the assessment of intelligence. Its administration is necessary for diagnosis, placement, and the design of an individualized educational program.


WISC-V categorizes its scales into primary indices, which represent cognitive abilities in five cognitive areas:

  1. Verbal Comprehension Index (VCI)
  2. Visual Spatial Index (VSI)
  3. Fluid Reasoning Index (FRI)
  4. Working Memory Index (WMI)
  5. Processing Speed Index (PSI)

The Full Scale IQ consists of seven out of the ten primary scales.

∗ The combination of these five factors provides the best prediction for academic achievement as well as basic clinical criteria.


Verbal Comprehension Index (VCI): Verbal Comprehension Index measures an individual's ability to understand and use vocabulary. Additionally, this index assesses language development, including the ability to listen, comprehend, and express oneself verbally.

Visual-Spatial Processing Index (VSPI): Visual-Spatial Processing Index evaluates an individual's ability to understand images, and visual and geometric relationships. Additionally, it assesses an individual's ability to perceive, store, analyze, recall, calculate, and think with visual stimuli.

Fluid Reasoning Index (FRI): Measures an individual's ability to quickly identify solutions to problems, as well as recognize relationships between visual objects. Additionally, it involves one’s ability to follow steps for solving a problem, to have inductive reasoning in mathematical concepts, and the ability of logical thinking.

Working Memory Index (WMI): Measures an individual's ability to encode, retain, retrieve, and manipulate both visual and auditory information in a short period of time. It also assesses the individual's ability to recall environmental interferences (e.g. sounds) and concentrate on the task at hand.

Processing Speed Index (PSI): Refers to how quickly an individual recognizes visual stimuli and makes decisions. Particularly under time pressure, it evaluates the individual's ability to remain focused. It also includes the ability for psychomotor coordination, that is, the use of the body to solve cognitive tasks.


Christia Paraskeva

School/Educational Psychologist

Collaborating Multithematic Center “MULTISENSE