Symbol Search compares two targets with a set of five symbols
In the WAIS Symbol Search subtest, the person compares two target symbols on the left with five symbols on the right and decides whether either target is present. They continue making present-or-absent decisions within a time limit.
In the Japanese WAIS-IV, Symbol Search is a core subtest of the Processing Speed Index, or PSI, together with Coding. Performance depends not only on finding a symbol but on quickly and accurately distinguishing similar shapes, deciding whether a match is present, and recording a response.
In the 2024 US WAIS-5, Symbol Search remains a primary PSI subtest, but it is not one of the seven subtests used to calculate FSIQ.
Correct and incorrect responses contribute to the raw score before age-based conversion
The Japanese WAIS-IV Symbol Search score is not based only on how many items the person reaches within the time limit. Correct and incorrect responses contribute to the raw score, so moving quickly while making frequent errors can lower the result.
The raw score is converted to a scaled score using age-based norms. A higher or lower scaled score therefore describes how quickly and accurately the person performed visual matching compared with people of the same age.
The task requires repeated visual search, matching, and decision-making
Each response requires a short sequence of processes:
- searching the five symbols for a possible match to either target;
- distinguishing symbols with similar orientations or details;
- deciding whether a matching symbol is present;
- marking the decision and moving immediately to the next item; and
- sustaining attention while the same matching process is repeated.
The central demands are visual search, shape matching, and a present-or-absent decision. A motor response is still required, but less written output is involved than in Coding, where symbols must be copied. Within processing speed, or Gs, Symbol Search particularly reflects how rapidly visual information can be found and turned into an accurate decision.
What higher and lower Symbol Search scores can show
A higher score indicates that the person was strong at distinguishing similar symbols, deciding accurately whether a target was present, and sustaining this process at an efficient pace.
A lower score can reflect slower visual search, repeated checking of similar forms, more time needed before deciding that no target is present, or more incorrect responses when the pace increases. A person who emphasizes accuracy and works cautiously may also complete fewer items within the limit. Characteristics of lower processing speed describes everyday situations in which related demands can appear.
If Symbol Search is clearly lower than Coding, scanning several symbols and deciding whether a match is present may have created more demand than writing symbols. If Coding is lower, handwriting and learning or retrieving number-symbol associations may have contributed more strongly. How to read WAIS results explains how to interpret the difference within the complete profile.
How Symbol Search differs from Coding and Cancellation
All three Japanese WAIS-IV subtests involve processing speed, but the repeated action is different.
| Subtest | Direct task | Processing emphasized |
|---|---|---|
| Symbol Search | Decide whether either target appears in a small set of symbols | Focused visual search, shape matching, and present-or-absent decisions |
| Coding | Write the symbol paired with each number | Searching and matching a key, written symbol production, and associative learning |
| Cancellation | Find and mark targets in a broad array of figures | Wider visual scanning, selective attention, and avoiding responses to distractors |
WAIS and BrainTypeIQ use similar Symbol Search formats with separate scoring
BrainTypeIQ Symbol Search also presents two target symbols and five search symbols and asks whether a match is present. Both tasks repeat visual search, matching, and decision-making within a short period.
BrainTypeIQ is administered online through on-screen buttons and uses a two-minute task with its own scoring method, which deducts points for errors. Its items, timing, scoring, administration, and comparison norms are separate from WAIS. The shared format gives BrainTypeIQ a strong, focused processing-speed task that contributes to its five-domain cognitive profile without treating the two tests or their scores as equivalent.