Leiter-3. Leiter International Performance Scale – Third Edition

Gale H. Roid, Lucy J. Miller, Mark Pomplun, Chris Koch
Polish standardization:
Anna Matczak, Aleksandra Jaworowska, Katarzyna Martowska
For persons aged 3–20
Individual and non-verbal. Administration times vary depending on age: for the youngest persons it's approx. 60 min., for the older persons – approx. 80 min.
Psychologists (MA diploma in psychology required)
C – for psychologists only

Description: The Leiter-3 is a tool designed to assess non-verbal intelligence, nonverbal memory and attention.

The Leiter 3 includes:

  • Cognitive Scales made up of five tests: Figure-Ground, Form Completion, Classification and Analogies, Sequential Order and Matching/Repeated Patterns (an additional optional test).
  • Attention and Memory Scales made up of another five tests: Attention Sustained, Memory Forward, Memory Reversed, Non-verbal Stroop Test and Attention Divided (an additional optional test).

The Leiter-3 is based on the hierarchical theory of intelligence by Cattell, Horn and Carroll.

The Leiter-3 is the only test which is entirely nonverbal. The examination is carried out without words which makes the test applicable for children with whom verbal communication is difficult or impossible.

The Leiter-3 is a new version of Leiter Scale already well known in Poland. Compared with the earlier version it allows to assess not only non-verbal intelligence but also attention and memory. It provides three composite indices: the Nonverbal Intelligence Quotient together with the Nonverbal Memory and Proceeding Speed Quotients. Subtest scores can also be interpreted which allow to evaluate reasoning abilities, eye perception, sustaining and dividing attention and also short term eye memory, working memory and ability to cope with interference.

Test scores together with the Nonverbal Intelligence and Nonverbal Memory Quotients may be expressed as Development Scores. The Leiter-3 is one few tests which allow to use Development Scores as well as to follow advances in cognitive abilities related to age or specific educational interventions. The Development Scores are susceptible of even minor changes which occur within the development process but which cannot affect the IQ. The Development Scores scale allows to evaluate effectiveness of therapy or development stimulating interventions as well as to observe development delays or regressive changes occuring with certain disorders or diseases.

The evident advantage of the Leiter-3 lies in the fact that it includes the Observation Scale. The scale was developped to detect non-typical behaviour features which can negatively affect child's functioning, that is, may create difficulties at school or in the sphere of social relations. The evaluation concerns the following dimensions: Attention, Impulse Organization and Control, Level of Activities, Gregariousness, Energy and Feelings, Self-regulation and Mood Regulation, Uneasiness and Sensual Reactivity.

In the standardization process the inferential norming procedure was applied based on the so-called continuous standardization method. The norms were developped for 44 groups from among general population (1 705 respondents) and for 40 groups from among the population of children with severe auditory impairement (576 respondents).

Calculated test scores are expressed on a 21-points scale where M = 10 and SD = 3. Composite scores are expressed on a scale of „Wechslerian” quotients where M  = 100 and SD = 15. The range of the Nonverbal Intelligence Quotient is 30-170 and that of the Nonverbal Memory and Proceeding Speed Quotients is 45-155.

Reliability: in both samples high internal consistency as well as high stability of composite scores on the Coginitive Scales and Attention and Memory Scales (the only exception being the youngest group from the general sample and the stability of the Nonverbal Memory scores); mostly high internal consistency for the Cognitive Scales tests and lower for the Attention and Memory Scales. Very high internal consistency and stability for the Observation Scale scores.

Validity: age-related changes of raw scores as expected; strong or moderately strong association of children's scores with their parents' levels of education. The Nonverbal Intelligence Quotient is positively correlated with the CFT 20-R Test scores and the Proceeding Speed Quotient with the Colors Trails for Children Test scores. Scores adequately differentiate children from the general sample and those intellectually impaired or with minor and moderate handicaps. The Leiter-3 scale scores are positively correlated with school grades of primary and middle school children and differentiate students in various types of high schools. Association was confirmed between the Observation Scale scores and temperament features: examinees from clinical groups scored lower on the Observation Scale than comparison groups members.

Norms:  for general population aged 3–20 and for children with severe auditory impairment aged 3–16.    

Applicability:  in psychological practice of intelligence, memory and attention assesssment. The Leiter-3 is esp. useful to examine persons with whom verbal communication is difficult or impossible as it requires neither the understanding nor the use of speech.                   

The complete set of materials includes the Polish version of a video presenting the Leiter-3 scale, its main features and examination procedures for all tests.

To use the Leiter-3 correctly the complete set of manuals is needed including:

  1. The original manual (translated into Polish) which comprises information about the administration procedure and detailed instructions for each of the 10 tests  together with rules to evaluate answers and calculate raw scores. All this information is not reproduced in other manuals. In addition, the first manual describes the development of the Leiter-3, its theoretical foundations and psychometric features of its orignal American version.
  2. The Polish standardized version which includes information about psychometric features of the Polish version (reliability, validity), a detailed description of scores calculation (converted scores, IQ, Development scores, age equivalents), rules of interpretation together with information about what can be concluded on the basis of each score as well as an example of case study
  3. The tables of norms which include all types of norms for general population and for children and adolescents with severe auditory impairement (converted scores, IQ etc.)


  • The complete set (aids in a bag, 25 test booklets, 25 transcript sheets, 2 kinds of score sheets 25 cop. each, 3 manuals)
  • Original manual
  • Manual for the Polish standardized version
  • Tables of norms
  • Test tools in a bag
  • Test booklet (25 cop.)
  • Transcript sheets for both scales (25 cop.)
  • Transcript sheets Nonverbal Intelligence (25 cop.)*
  • Development score sheets for children with severe auditory impairment (25 cop.)
  • Development score sheets for general population (25 cop.)

* At the request of our customers, who sometimes use the Leiter-3 to study nonverbal intelligence only, we have launched a new type of sheet to study only this area. These sheets are not included in the kit.


Please note: All of our tests are published in Polish. There are not available other language versions of our tools.

Secondary menu


Wskaż newsletter, który chcesz zasubskrybować, lub z subskrypcji którego chcesz zrezygnować.