Next, we need to tell Experiment Builder when the answer is correct or incorrect. Notice in our datasource we already have a column called “expected_button” which lets us know which button press is correct for each trial. We can use this information to create what is called a “Conditional Statement”. Conditionals are common in programming, but they follow the logic of:

• IF response is correct do something
• IF response is incorrect do something else

In our case, the conditional will appear after the KEYBOARD response but before UPDATE_ATTRIBUTE. We want to play the error sound only when the response is incorrect.

Conditionals and Feedback

To do this, let’s begin by creating a new variable to record accuracy. We do this in the same way we created RT and BUTTON_PRESS earlier:

• Create a new variable called RESPONSE_ACCURACY
• Set the default value as any number that you won’t use i.e. we will use 0 and 1 for correct and incorrect, so I set the default as 999

This process is shown below.

We now need to insert some new actions and triggers. Follow these steps:

• Delete the link between KEYBOARD and UPDATE_ATTRIBUTE
• Drag a CONDITIONAL Trigger from the Trigger bar
• Notice it is shaped like a triangle and the button two points have a cross and a tick
• We will give the triangle a conditional statement : this is sketched out below.

Click on the new CONDITIONAL and look at the Properties panel. Instead of what is in there at the moment, we want to say: if the keyboard press is correct, as stated by the column “expected_button” in the Data Source then the conditions have been met. Or to put it another way,

 IF 

KEYBOARD.TriggeredData.key 

EQUALS 

Data Source.expected_button THEN [DO SOME ACTIONS]. The start of this is shown below.

So IF the condition is met and the KEYBOARD response is the same as the expected_button in the datasource then we follow the corner of the CONDITIONAL Trigger with the tick on it. Here’s a diagram showing this:

Next, we need to set up the RESPONSE_ACCURACY in UPDATE_ATTRIBUTE. Here are the steps to follow, with an animation below:

• Click on UPDATE_ATTRIBUTE and in the Properties panel click on Attribute-Value List
• Set the Attribute as the RESPONSE_ACCURACY variable. Remember the Attribute is what you want to change
• Set the Value to 1. Remember the Value is what you want the Attribute to be changed to. Typically, a value of 0 is used for incorrect and 1 is used for correct, but you can use whatever values you like.

Next, join the side of the CONDITIONAL with the tick to the UPDATE_ATTRIBUTE, as shown below, and then that side is complete!