Variable and Values

The name of the variable and the list from which it takes the values.

Related Variables

You can add and remove related variables according to whether you want them to have the same selection method as the first variable or not.

The number of possible values for all the related variables must be the same. Therefore, all the lists from which these variables obtain values must have the same number of elements.

Selection Method

The different methods used for the variables to get their values from their list.

• all values in order: The variable gets all the values from the list in order.
  • selectionMethodPriority: The priority of the method.
    For example:
    First variable gets its values in order and its possible values are: 0, 1.
    Second variable also gets its values in order and its possible values are 10, 20, 30.
    Depending on which variable has a higher priority the result can be:
    • 0,10
    • 0,20
    • 0,30
    • 1,10
    • 1,20
    • 1,30
      if the first variable has higher priority, or:
    • 0,10
    • 1,10
    • 0,20
    • 1,20
    • 0,30
    • 1,30
      if the second variable has higher priority.
      
  • alternatedVariable: There can only be one variable (or group of variables) of alternate type. This variable goes through all its values (in order or randomly) before starting with another repetition of all its values.
    
    
    
• all values in random order: The variable gets all the values from the list in random order.
  • alternatedVariable: There can only be one variable (or group of variables) of alternate type. This variable goes through all its values (in order or randomly) before starting with another repetition of all its values.
    
    
    
• one fixed value: The variable value is always the same fixed value from the list.
  • positionValue: Select one of the values from the list. From 1 to the total number of values.
    
    
    
• one random value: In each trial, the variable value is a random value from the list.
  • selectionMethodEqual: Whether or not the selection of values ​​for all the related variables is the same.
    • equal: All the related variables take a value that is in the same position in their respective lists.
    • different: All the related variables take a value that is in a different position in the list for each variable.
      The number of variables must be less or equal than the number of possible values in the lists to meet this condition.
      
      
      
• depends on correct: The variable value depends on the correction of the previous response.
  • correct/incorrect: After a correct response, the variable value is the first value from its list.
    After an incorrect response, the variable value is the second value from its list.
    If there has been no response yet, the previous response is considered correct. So in case the variable is used before giving any response, the variable value is the first value from its list.
  • 1up/1down: After a correct response, the variable steps down, to the previous value in its list.
    After an incorrect response, the variable steps up, to the next value in its list.
  • 1up/2down: After two consecutive correct responses, the variable steps down, to the previous value in its list.
    After an incorrect response, the variable steps up, to the next value in its list.
    To get to the relevant values faster, a 1up/1down method is applied until the first incorrect response, then the method changes to 1up/2down.
  • 1up/3down: After three consecutive correct responses the variable steps down, to the previous value in its list.
    After an incorrect response, the variable steps up, to the next value in its list.
    To get to the relevant values faster, a 1up/1down method is applied until the first incorrect response, then the method changes to 1up/3down.
  • initialValue: Select one of the values from the list. From 1 to the total number of values. This will be the first value. From there, the value will change following the chosen formula.

Blocks

When the values of a variable are in a list of Blocks there is no selection method. The list of blocks manages how the values are chosen.

Examples of use:

Using one block

Suppose you want the values of a particular variable to alternate between two lists in each trial. For example you want that if the value in the n trial is positive, the value in the n+1 trial is negative and vice versa.

First create the two lists of numerical values:

• In the first list the values are: 1, 2, 3, 4.
• In the second list the values are: -1, -2, -3, -4.

To make the alternation possible you need to create a list of blocks. And set the following values:

• Repetitions
  • numberOfBlocks = 1
  • lengthOfBlocks = 10
• Types of blocks
  • typesOfBlocks = 1
• Block
  • firstList = your first list of values
  • secondList = your second list of values
  • startingList = random
  • probChangeList = 1

When a variable takes its values from a list of blocks, it is assigned an initial list, in this case, one of the two lists is chosen randomly. After each trial, the list changes with a certain probability (in this example with probability one). For each trial, the value of the variable is chosen randomly from the values in the corresponding list.

If you preview the variable values, you will get something similar to:

-2, 4, -4, 1, -1, 2, -3, 1, -3, 4

Using two blocks

Suppose you want the values of a particular variable to be be sometimes in repetition blocks and other times in alternation blocks. This means that in certain blocks it is more likely to repeat the same list and in others it is more likely to alternate it.

First create two lists of numerical values:

• In the first list the values are: 1, 2, 3, 4.
• In the second list the values are: -1, -2, -3, -4.

Then, create the list of blocks. And set the following values:

• Repetitions
  • numberOfBlocks = 5
  • lengthOfBlocks = 10
• Types of blocks
  • typesOfBlocks = 1
  • startingBlock = random
  • probChangeBlock = 1
• First Block
  • firstBlockFirstList = your first list of values
  • firstBlockSecondList = your second list of values
  • firstBlockStartingList = random
  • firstBlockProbChangeList = 0.2
• Second Block
  • secondBlockFirstList = your first list of values
  • secondBlockSecondList = your second list of values
  • secondBlockStartingList = random
  • secondBlockProbChangeList = 0.8

The first block is chosen randomly between the repetition block (with probability of changing list = 0.2) and the alternation block (with probability of changing list = 0.8).

Blocks consists of 10 trials and the probability of changing from one block to the other is 0.5, that means that the type of block is chosen randomly when the previous block ends.

If you preview the variable values, you will get something similar to:

2, 2, 1, 4, -2, -2, -4, -1, -2, -3 repetition block

-1, -3, -2, 1, 4, 4, 4, 1, 4, 4 repetition block

-3, 4, -1, 4, -4, 2, -2, 1, -3, 3 alternation block

1, 2, -2, -3, -3, -4, -2, -3, -2, -2 repetition block

4, -2, 3, -2, 1, 4 ,-3, 3, -3, -4 alternation block