___________________________________________________________________________________________________________________ Brief Leiter International Performance Scale ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 08-01-2022 last updated: 02-15-2024 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-15-2024 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements Millisecond Software's computerized version of the Brief Leiter International Performance Scale as described in Leiter (1936). The Leiter International Performance Scale is a non-verbal performance scale devised for children ages 5-16 (Leiter, 1936). It is played with 5-8 wooden blocks with printed images on them that have to be moved into respective slots on a wooden frame. It is a strictly non-verbal test as participants are not given any verbal instructions (other than very limited ones at the beginning) nor are any of the problems language-related. The Inquisit computerized adaptation re-creates the wooden frames and blocks on the screen. The initial instructions are minimal but let participants know that objects need to me moved around on the screen with their fingers. In addition, some of the problems present a computerized hand moving the first block into its respective slot to give participants some idea of what needs to be done. Reference: Leiter, RG (1936).The Leiter International Performance Scale. UNIVERSITY OF HAWAII BULLETIN, 7, 1-42. with appendix by S.D. Porteus ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ This script implements the subset of the Leiter problems ages 5 to 16 as described in Leiter (1936) and referred to as the 'Brief Leiter Scale'. Year 5 to Year 10 include 2 problems per age level, year 11 to year 16 include one problem per age level. By default participants start with the year5 problems and work their way up to the year16 problem. The order as well as the type of problems presented can be easily edited. For each problem, participants see a 'wooden' frame with 5-8 slots (the number of slots depends on the problem) and some images printed above each of these slots. In addition participants see 5-8 'blocks' (exception: year10_2 problem) that need to be moved into a matching slot on the frame. The rule for matching 'block to slot' needs to be discovered by the participant. No verbal cues are given. For some problems, a hand appears and does the matching for the first slot item to give participants some idea of what the matching criteria could be. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 15 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'leiterinternationalintelligencetest_raw*.iqdat' (a separate file for each participant) build: The specific Inquisit version used (the 'build') that was run computer.platform: the platform the script was run on (win/mac/ios/android) date, time: date and time script was run subject: with the current subject id group: with the current group id session: with the current session id dob: participant's date of birth values.gender: participant's gender blockcode, blocknum: the name and number of the current block (built-in Inquisit variable) trialcode, trialnum: the name and number of the currently recorded trial (built-in Inquisit variable) Note: trialnum is a built-in Inquisit variable; it counts all trials run; even those that do not store data to the data file. Note: trial.evaluate stores the final accuracy and response time values for each problem problemCount: counts the number of problems worked on default setting: there are max. 20 problems that participants can work through problem: stores the problem assignation (e.g. 'y5_1': year5 problem, first problem) problemAge: the age assigned to the problem (e.g. y5_1: 5, y5_2: 5.5) slots: the number of slots for the current problem problemRT: the response time (in ms) for the current problem (correct or incorrect responses) trial.matchingTask.lastdropsource: stores the last block moved trial.matchingTask.lastdroptarget: stores the last slot targeted itemSlotPlacement: stores the block placement for the given slots (0 = no block has been moved to this slot yet) Example: 5 slot problem: 21300 => participant placed block2 into slot1 (incorrect), => participant placedblock1 into slot2 (incorrect) => participant placedblock3 into slot3 (correct) => participant has not moved any block into slot4 => participant has not moved any block into slot5 list.ACC_problem.mean: proportion correct across all problems ageLevel: the highest age level that participant reached before making the first mistake maxLevel: the highest age level problem correctly solved yearCredit: the year credits accumulated (start at 4.5) year5-10: receive 0.5 per correctly solved problem year11-16: receive 1 point per correctly solved problem the maximum: 16.5 response: the response of participant (scancode of response button) correct: correctness of response (1 = correct, 0 = error) latency: response latency (in ms); measured from: trial onset (2) Summary data file: 'leiterinternationalintelligencetest_summary*.iqdat' (a separate file for each participant) inquisit.version: Inquisit version run computer.platform: the platform the script was run on (win/mac/ios/android) startDate: date script was run startTime: time script was started subjectid: assigned subject id number groupid: assigned group id number sessionid: assigned session id number elapsedTime: time it took to run script (in ms); measured from onset to offset of script completed: 0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run) ageLevel: the highest age level that participant reached before making the first mistake maxLevel: the highest age level problem correctly solved yearCredit: the year credits accumulated (start at 4.5) year5-10: receive 0.5 per correctly solved problem year11-16: receive 1 point per correctly solved problem the maximum: 16.5 ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ (I) Demographic Information: this script collects gender and date of birth information (II) Instructions (III) Subtests (in order, see list.subtests) Subtest Descriptions from Leiter (1936, starting at p.34) (1) Year 5 Problems: 1. 'Matching Forms. Use the seven notch frame for the test. Seven of the simpler of the Kuhlmann forms are used. The seven forms on the strip and the seven forms on the blocks are identical. The subject is expected to place like forms together.' Note: because this is the first test and the material is all virtual, this script provides a computer hand that moves the first block into its slot to give the participant an idea of how to go about the solution of this test (the hand can be turned off under section Editable Parameters) 2. Picture Completion. 'Use the five notch frame for this test. Five colored pictures have been so cut and mounted that the upper halves are on the strip above the notches and the lower halves are on the blocks. The subject is expected to place the blocks in the notches -where they will complete the picture on the strip. The examiner should give the subject an idea of how to go about the solution of this test by completing the picture of the ball over the first notch.' (2) Year 6 Problems: 1. Color-Form Test. 'Use the eight notch frame for this test. The strip has on it orange and green squares and triangles each figure having on it either one or two blue dots. The blocks have identical combinations on them. This makes three things which the child must match: form, color, and number of dots. All three of these elements must be correct in each notch. However, the position of the block, i.e., whether it is side ways, upside down, or right side up, does not affect the score.' 2. Association by Use. 'Use the five notch frame. On the strip are drawn the pictures of a hand, a man's head, a foot, a baby, and a girl's head. The blocks contain the pictures of a glove, a man's hat, a shoe, a' baby's dress and a girl's hat. The subject is expected to place the blocks containing the pictures of articles of clothing in the notches underneath the particular part of the body where they are worn.' (3) Year 7 Problems 1. Size Gradations. 'Use the five notch frame. The strip for this test has drawn on it a series of circles of increasing size from a small one on the left hand end to the largest of' the series on the right hand end. The blocks have drawn on them an analogous series of squares. The subject is expected to place the smallest square with the sm~llest circle and the next larger square with the next larger circle and so on until the series of squares in the notches are analogous to the series of circles on the strip.' 2. Matching Two-Color Circles. 'Use the six notch frame. 'On the strip are mounted six circles one inch in diameter. Each one is made up of two colored halves, the division being on the vertical. The blocks for this test have the same kinds of circles on them as are found on the strip. The task set the child is to find the two-colored circle on the block which will match the two-colored' circle on the strip. The correctness of the selection of the block and not the position in which it is placed in the notch determines the score.' Note: this script presents half the block images rotated by 180degrees (the colored halfs appear flipped). (4) Year 8 Problems 1. 'Animal Classification Test. Use the five notch frame. On the strip are drawn the pictures of a bird, a cow, a crocodile, a lion, and a butterfly. On the blocks are drawn the pictures of an owl, a horse, a frog, a tiger, and a bee. It will be seen that the five animals drawn upon the blocks can be matched to the five drawn on the strip on the basis of their habitat. The two birds going together, the two domesticated animals going together, the two animals that live in the water going together, the two wild animals going together and the two insects going together.' 2. Completing a Series.' Use the eight notch frame. There are two forms for this test. The strip for the first one is marked VIII-2 A. This strip is placed on the frame first. The first five notches only are marked. The marks are X 0 X 0 X. The remaining three notches are blank. The blocks that go with this strip are four of .the X blocks and four of the 0 blocks. If the subject is able to complete the series in the unmarked notches the second form or form B should be given. The strip for the second form is marked VIII-2 B. As on the strip for the first form, only the first five notches are marked. J'he marks are - X - X -. The blocks that go with this strip are four X blocks and four - blocks. If the subject is now able to complete this form also he is given credit for the test. Both forms must be correct to receive credit. Auto-criticism on this test is only possible when just enough of the proper blocks are placed before the subject to complete each form correctly. All of the X, 0, and - blocks should not be left out for the subject to choose from.' (5) Year 9 Problems: 1. 'Completing a Series. Use the eight notch frame. This test is a continuation of the VIII-2 test and must be preceded by it. Again two forms are used. The strip for the first form is marked IX-l A. Only the first four notches are marked. The marks are: 0 - X O. The remaining four notches are blank. The blocks that go with this test are those that were used with the VIII-2 test. Here too, only enough blocks to complete each form correctly with no left overs should be placed before the subject. For form A put out three 0 blocks, three - blocks and two X blocks. If form A is done correctly go on to form B. Use the strip marked IX-I B. The same blocks are used for form B as were used for form A. If form B is passed also, credit is given for this test.' Note: no visual of the second form was availabe to Millisecond Software to recreate form IX-I B. Millisecond Software used series '- O X -' for the second test instead. 2. Recognition of Age Differences.' Use the five notch frame. On the strip are pasted five half tone photographs one inch by one and one fourth inches of five different African native females at different stages of growth. On the left hand end there is a baby. The second picture is that of a girl of about twelve years; the third picture h; that of a young woman of about twenty-two; the fourth is that of a middle-aged woman about forty-five; and the fifth is the picture of an old woman of about seventy years. On the five blocks are the half tone pictures of five African native males of analogous ages. The subject is expected to recognize the age differences in each series and to see that the blocks can be matched to the pictures on the strip on a basis of age.' NOTE: this script runs the original Leiter images that depict drawings of old-fashioned Caucasian faces. The script also provides black/white photos of Black faces BUT they are not the originals used by S.D. Porteus (in Leiter, 1936). The alternative images in this script were downloaded from https://pixabay.com and edited to appear more like drawings. (6) Year 10 1. Matching Shades of Grays. Use the eight notch frame. One inch gray paper squares of the eight standard shades of gray are mounted on the strip. The blocks have the same shades pasted on them. The test problem involves the careful comparison of each shade on the strip with each block until the exact duplicate is found. Note: to create the gray stimuli for this script, the originals were photographed and the colors that appeared in the photograph were used to create the different gray stimuli. 2. Matching Forms (Advanced). Use the five notch frame. This test is an adaptation of Test 2 in the Detroit First-Grade Intelligence Test devised by Anna M. Engel. The forms should be arranged before the subject in the order shown in the illustration of this test, i.e., like forms in a row. The test is made considerably more difficult if the blocks are scattered at random on the testing table. The forms have not been altered. The writer has merely made a performance test out of this material. The test locates at a higher year level in the Leiter scale due to the elimination of instructions and the additional requirement that all forms must be correctly matched in order to receive credit. The examiner places the first and easiest form for the subject. No help is given· after this. The subject must fill the other four notches correctly by himself if he is to receive credit for the test. (7) Age 11 1. Line Completion Test. Use the eight notch frame. The strip has a heavy' black line on it that drops down to each of the eight notches at varying angles and is broken and incomplete until one of the complementary blocks is placed in the notch to complete it. The examine!; should see that all of the blocks face the right way; otherwise the nature of the task is not clear. Sometimes the subject gets the idea that he is to match the angles of the line above and not to complete it. This may even happen after the placing of the first block by the examiner if the blocks are turned around. After the material is in proper position the examiner places the first block in notch one (the blocks for notch one and eight are the same) and runs his pencil or forefinger over the line to show that it is complete. To children this is much the same as completing a railroad track. After this the subject is left to his own resources. It is well to note the type of response on this test, i.e., whether the child goes about the task by a trial and error procedure or whether he does it by insight. (8) Age 12 1. Matching Footprints Test. Use the eight notch frame. This test is adapted from the Porteus Footprints test. Eight footprints of Australian aborigines are mounted on the strip above the eight notches. The same footprints appear on the eight blocks that make up the balance of the test material. The subject is- expected to match the pictures on the blocks with those on the strip. (9) Age 13 1. Dot Estimation Test. Use the eight notch frame. This test is an adaptation from the Porteus Dot Estimation test. The strip has a square drawn over the first notch which contains fifteen dots and a square over the eighth or last notch which contains seventy dots. The intervening spaces are blank. The blocks have the following numbers of dots on them: 15, 20, 25, 30, 40, 50, 60, and 70. The task set the subject is to arrange the masses of dots in order from least to most. The arrangement of the dots on the strip makes this task self evident and no help is necessary. The number of dots on each block is written on the under side. The subject should not be allowed to examine these numbers. Note: the actual number of dots on the original blocks differ from the above described ones. (10) Age 14 1. Association on a Basis Superior to Use. Use the six notch frame. The strip has the drawing of a glass bottle, a pair of scissors, a wooden block, a tree, a book, and a bird on it. The blocks contain pictures of a glass, a penny, a chair, a flower, an envelope, and a cow. At the six year level we found that children could match by associating the article with its use. At eight years two articles of similar uses could be placed together. Here a higher type of response is required as these articles will not match up by these principles. Note: this script runs the stimuli as described above. Some of the images needed to be re-created. (11) Age 15 1. Opposites Test. Use the six notch frame. Drawn on the strip are: a circular arrow, a one-inch white square, an African native woman, an L, a small square, and a straight arrow. Drawn on the blocks are: a circular arrow in reverse from the one on the strip, a black square, an African native man, an L in reverse, a small circle, and a straight arrow. The figures and pictures on the blocks are all the reverse of those on the strip. When the blocks are placed before the subject the straight arrow should be held in a vertical position at the right end of the frame by the examiner until the first five notches have been filled. During the time that the subject is working on the first five notches the examiner may give any help that may seem necessary. The test is scored right or wrong entirely on the position of the arrow in the last notch. Here the arrow must be placed so that it is pointing in the opposite direction from the one on the strip. If the subject gets the idea of the test and sees that all of the first five notches have been filled on the principle of opposites he will of course be able to place the straight arrow in the proper position. Note: this script runs an adapted procedure as it is currently not possible to rotate the last arrow into the correct direction. Thus, this test presents two last arrows. One pointing left and the other pointing right. Participants have to match the arrows based on the opposite principle. (12) Age 16 1. Position Analogy Test. Use the seven notch frame. This test is an adaptation of the Ableson test found in the Army Alpha test. The seven drawings on the strip of the overlapping square, triangle, and circle, are indentical in all respects save the location of the dot, which appears in seven different locations. The blocks have identical combinations of square, triangle, circle, and dot but the triangles vary in shape thus causing the subject to soon find out that form matching is not the principle by which the test can be put together. Scoring: All participants are asked to work through all tasks. For problems year5-10, participants receive 0.5 points for correct problem completion (2 problems per age); For problems year11-16, participants receive 1 point for correct problem completion ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ Stimuli are either based on original Leiter material or recreated by Millisecond Software based on the original Leiter material as well as the descriptions provided in Leiter (1936). ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ provided by Millisecond Software - can be edited under section 'Editable Instructions' ___________________________________________________________________________________________________________________ EDITABLE CODE ___________________________________________________________________________________________________________________ check below for (relatively) easily editable parameters, stimuli, instructions etc. Keep in mind that you can use this script as a template and therefore always "mess" with the entire code to further customize your experiment. The parameters you can change are: