Tangrams Puzzle Task

Technical Manual

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond

Created: January 25, 2016

Last Modified: January 20, 2023 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a Tangram script inspired by: www.abcya.com/tangrams.htm

Tangram = a puzzle consisting of seven simple 2D geometric shapes (called tans). The goal is to use all 7 pieces to form a more complex 2D shape.

Duration

15 minutes

Description

Participants are given 7 individual geometric shapes and are asked to use them to create 6 complex figures. Shapes can be moved via drag and drop. Once a shape is moved, it moves into "rotation mode" and can be rotated via a rotation console that is located at the bottom right of the screen. During "rotation mode", no drag and drop can happen. The rotation mode is exited via a click anywhere on the canvas (with exceptions of the rotation arrows). By default, the task is self-paced.

Procedure

• 1 practice tangram
• 6 tangrams are presented in predetermined order
(by default - order can be randomized/changed -> list.tangramPresentationOrder)
• the 7 shapes are presented in the same screen positions but with a randomly determined rotation angle
( start angle can be edited under list.selectStartitemnumber)
• no time limit for solution (self-paced)
• participants can either move the individual shapes around or rotate them in a 2D plane by
45degrees using a provided
"Rotation Console" on the lower right of the screen
• solution is submitted by clicking on a "submit" button

Algorithm to determine correct placement of shapes:
- the algorithm to determine the correct placement of shapes assumes that
the provided shapes are being used - it might not function properly with
a different assortment of tangrams nor a different assortment of simple shapes
- it compares the final rotated angle of each shape with all possible correct
rotations for this particular shape and then (if a match is found)
- checks whether the final shape coordinates are within the tolerated distance of the correct
coordinates for this particular rotation.
(algorithm doesn't check placement if the shape is not rotated to the/any correct angle)
- for identical shapes it is also checked if the shapes occupy different
areas of the tangram figure (as they cannot sit on top of each other)

Stimuli

6 tangrams and 5 different shapes are provided by Millisecond (www.abcya.com/tangrams.htm)-
if different tangrams are used, the lists for each tangram as well as the
algorithm for correct responses need to be adapted accordingly.

Instructions

provided by Millisecond - see section Editable Instructions

Summary Data

File Name: tangrams_summary*.iqdat

Data Fields

NameDescription
inquisit.version Inquisit version number
computer.platform Device platform: win | mac |ios | android
startDate Date the session was run
startTime Time the session was run
subjectId Participant ID
groupId Group number
sessionId Session number
elapsedTime Session duration in ms
completed 0 = Test was not completed
1 = Test was completed
nrCorrect Number of correctly solved Tangrams
propCorrect Proportion correctly solved Tangrams
meanRT Mean latency (in ms) of correctly solving a Tangram
sdRT Standard deviation (in ms) of the latencies of correctly solving a Tangram
tangram1Correct 1 = tangram 1 was correctly solved; 0 = otherwise
tangram1Duration Duration (in ms) of tangram1 solution
(same for all 6 tangrams)

Raw Data

File Name: tangrams_raw*.iqdat

Data Fields

NameDescription
build Inquisit version number
computer.platform Device platform: win | mac |ios | android
date Date the session was run
time Time the session was run
subject Participant ID
group Group number
session Session number
blockCode Name of the current block
blockNum Number of the current block
trialCode Name of the current trial
trialNum Number of the current trial
practice 1 = practice trial; 0 = test trial
countTangrams Counts the number of Tangram test problems presented
selectAngle Stores the rotation angle of the currently presented test tangram
(1 = 0°, 2 = 45°, 3 = 90°, 4 = 135°, 5 = 180°, 6 = 225°, 7 = 270°, 8 = 315°)
responseSelection Trial.evaluateTamgram: stores 'submit' once the submit button was pressed
sumRT Latency (in ms) of each tangram solution attempt.
Measured from onset of tangram to pressing of "submit" button
acc 1 = all 7 shapes were correctly placed; 0 = otherwise
!!! the algorithm determineCorrectResponses may not work correctly if
different tangrams are used.
correctPlacements Number of correct placements (Max = 7)
correct placement = orientation of shape is correct AND
its center is within paramters.max_deviationTolerance (default: 5%) of the correct center coordinates
!! the algorithm determineCorrectResponses may not work correctly
if different tangrams are used.
correct1-
correct7 1 = shape was correctly placed on tangram; 0 = otherwise (for each of the 7 shapes)
!!! the algorithm determineCorrectResponses may not work correctly
if different tangrams are used.
for shapes 1-7 Shape 1/2: big, red triangles
shape 3/4: small, yellow triangles
shape 5: purple diamond
shape 6: green triangle
shape 7: orange parallelogram
! please keep in mind that shape1/2 and shape3/4 are interchangeable.
Furthermore, for some configurations alternative angles (not stored in the datafile) for several shapes can be correct as well,
these alternative
correctRotation1ItemNumber The correct angle number stored for the rotated stimuli for shape 1-7
(1 = 0°, 2 = 45°, 3 = 90°, 4 = 135°, 5 = 180°, 6 = 225°, 7 = 270°, 8 = 315°)
select1 The selected itemnumber of the rotated stimuli for shape 1-7
correctX1 The correct horizontal percentage coordinates for shapes 1-7
correctY1 The correct vertical percentage coordinates for shapes 1-7
finalX1 The final horizonal percentage coordinates for shapes 1-7 ( if shape was NOT moved, the pixel converted percentages are off)
finalY1 The final vertical percentage coordinates for shapes 1-7 (Note; if shape was NOT moved, the pixel converted percentages are off)
(same for remaining shapes)

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
maxDeviationTolerance The acceptable percentage difference between the correct placement of the images and the final placement of images (=center of image)
to still be evaluated as correct (if the shape is correctly rotated)
'correct' placement coordinates were determined by manually clicking on the centers of the
correctly positioned shapes and recording the corresponding percentage coordinates in the data file.