Symbol Search compares targets with a small set of symbols
In the WAIS Symbol Search subtest, the person compares target symbols with a small search set and decides whether a match is present. They continue making present-or-absent decisions within a time limit.
In 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 WAIS-5, Symbol Search remains a primary PSI subtest, but it is not one of the seven subtests used to calculate FSIQ. Both speed and accuracy matter. WAIS-IV and WAIS-5 compared explains the wider change in subtest roles.
Each response repeats a short sequence:
- searching the symbol set for a possible match to a 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. Less written output is involved than in Coding. Within processing speed, or Gs, Symbol Search especially 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.
The same processing is used when repeatedly finding entries in a list or table and checking that each one is correct.
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, Cancellation, and Naming Speed Quantity
These subtests all 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 |
| Naming Speed Quantity | Recognize quantities and say the corresponding numbers aloud | Rapid quantity recognition and spoken label access with reduced written output |
WAIS and BrainTypeIQ share the same visual-search task format
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 uses on-screen buttons, keeping the focus on rapid visual search, accurate matching, and present-or-absent decisions without adding handwriting speed.