Task Details

 

The matrix span task simply presents participants with grid locations to remember in sequence. The grid used is a 4x4 grid. After receiving all the grids that they must remember participants are notified it is the recall phase and they must click the grids in the order they recall seeing them.

Screenshots

 

Presentation Phase

Image shows a 
			screenshot of what the program looks like while delivering the presentation phase of 
			the task

Recall Phase

Image shows a 
			screenshot of what the program looks like while delivering the recall phase of the 
			task after receiving two inputs

The XML

 

You can download the default XML here. In this section I will point out the customisation options at your disposal by modifying values in the XML.

Under task settings there is a section of code where we tell the application where to find the executable that handles the digit span task. The property name/value keys here are where we can set task-specific properties.

Number of trials

You can select how many trials of each span size you want. The properties to edit here are:

  • 'spanTwoTrials'
  • 'spanThreeTrials'
  • 'spanFourTrials'
  • 'spanFiveTrials'
  • 'spanSixTrials'
  • 'spanSevenTrials'
  • 'spanEightTrials'
  • 'spanNineTrials'
The default values for these properties are "3" for spans 2 through 7 and "0" for spans 8/9. Therefore as it stands the module will administer 3 trials at each list length up to 7 and none at list length 8 or 9. Simply change the integer values within the quotes for each span*Trials property to get the desired number of trials.

Sequential/Randomised trial order

This property decides if the trials are administered in sequential order or not with regards to the list lengths. If sequential then all list length 2 trials are given, followed by all list length 3 trials, and so forth. However, it is often the case that a researcher may wish to administer these trials in a random order so that the participant is not aware on any given trial how many digits they will have to store/recall. The property to edit is:

  • 'randomisedTrials'
The default value is "0" which is the code for sequential order. The alternative is "1" which is the code for random order.

It is possible to select how many grids you would like in the matrix. The property responsible is:

  • gridDimension
Whatever number(n) is set as the value will decide how many grids are in the matrix (n x n). the default is 4 which creates a 4x4 matrix hence 16 grids.

In addition there is an option to control the actual size (on screen) of the matrix.

  • ScalingFactor
The application will get the size of the screen and it is being executed on (in pixels) and initially create the matrix to be as large as it can be while still fitting the screen. It then applies the scaling factor (treat as a percentage). So if you want the matrix to be half size then this value can be set to 50. The optimum value will differ depending on the equipment used and researcher preference.

Data Analysis

 

After running the matrix span processing script (download from here) you will get a data frame with the following variables. Information on running the script and obtaining the processed data is here

Variable Name Description
fta.score This is the score the participant achieved when the full-trial accuracy scoring method is used.
prop.score The score obtained by the participant when the proportion correct method of scoring is used.
number.successes The score obtained by the participant when the number of correctly recalled elements method of scoring is used.
max.span Maximum list length at which the participant successfully recalled all the elements in the trial.
span.2.corr Number of trials successfully answered (all grids recalled) at list length 2 - "NA" value if there were no trials at this list length administered
span.3.corr Number of trials successfully answered (all grids recalled) at list length 3 - "NA" value if there were no trials at this list length administered
span.4.corr Number of trials successfully answered (all grids recalled) at list length 4 - "NA" value if there were no trials at this list length administered
span.5.corr Number of trials successfully answered (all grids recalled) at list length 5 - "NA" value if there were no trials at this list length administered
span.6.corr Number of trials successfully answered (all grids recalled) at list length 6 - "NA" value if there were no trials at this list length administered
span.7.corr Number of trials successfully answered (all grids recalled) at list length 7 - "NA" value if there were no trials at this list length administered
span.8. corr Number of trials successfully answered (all grids recalled) at list length 8 - "NA" value if there were no trials at this list length administered
span.9.corr Number of trials successfully answered (all grids recalled) at list length 9 - "NA" value if there were no trials at this list length administered
user The value of the username of the account which produced the data