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Circular Matching Task

Try the Demo

In this task, a reference stimulus is presented in the middle, surrounded by a ring of other stimuli; any number of these alternatives can be selected by the participant. This is an efficient way to set up a same-different paradigm.

Example Circular Matching task

Example Circular Matching task, with 2 stimuli selected

Below you'll find information specific to the Circular Matching task. This assumes you're familiar with how to setup an experiment and how to select stimuli for a given task.

Parameters

Customize the task by changing these on the Parameters tab of the task.

General Interface settings

Customize the instruction at the top of the page, as well as toolbar buttons. These apply to most task types on Meadows.

Instruction hint

Text that you can display during the task at the top of the page.

Extended instruction

A longer instruction that only appears if the participant hovers their mouse cursor over the hint.

Hint size

Whether to display the instruction, or hide it, and what font size to use.

Fullscreen button

Whether to display a button in the bottom toolbar that participants can use to switch fullscreen mode on and off.

Trials and stimuli

Control the number of trials, as well as the number of stimuli per trial.

Number Of Alternatives

How many option stimuli to display around the reference. This only applies if you let the task generate random trials, and is ignored if you use a Trial File.

Maximum Number Of Trials

How many trials to generate from the selected stimuli. For a large number of trials, keep in mind that all stimuli have to be loaded at the start of the task. Consider spreading the trials over multiple Circular Matching tasks. Default is 10.

Blank Duration

For this duration, the screen is cleared between trials. Set to 0 to turn this off. Default: 500 ms.

Spatial configuration

Options for customizing the lay out of the screen during the task.

Item Size

Height of the stimuli in % of the width of the field. Default 8%. Must be between 2% and 20%. The width is adapted according to the original aspect ratio of the image.

Randomize Locations

By default the stimuli start out surrounding the circle, this puts them to the right and left

Selected Outline Thickness

Width of the border that is displayed around selected items, in dots. Set to 0 to hide. Default: 30.

Selected Outline Color

Color of the border around selected items. Default: Red.

Data

For general information about the various structures and file formats that you can download for your data see Downloads.

Pair-wise "annotations" (table rows). The rows are in the same order as the stimuli were displayed in a trial. Columns:

  • trial numerical index of the trial
  • time_trial_start When the trial was displayed
  • time_trial_response When the participant confirmed their selection
  • stim1_id meadows internal id of the reference stimulus
  • stim1_name filename of the reference stimulus as uploaded
  • stim2_id meadows internal id of the stimulus to match
  • stim2_name filename of the stimulus as uploaded
  • label "true" if selected, "false" otherwise.