Experiment File Examples - Moderate Complexity

Is current?: 
Yes

This entry describes how to create an experiment file so that tasks can be counterbalanced during the study using the "jjoy.moderate" file (downloadable at the bottom of this page).

Definitions

Looking at the definitions, you see that we have a the standard files included: the start page, the consent, and the debriefing. In addition, we have a task called "dropdown" as well as a race IAT and IAT instruction page. Notably, we have two IATs (iatrace1 and iatrace2). As with most experiments, we are using two IATs to ensure we can counterbalance the order of pairings.  

<Definitions>
<Task id="startpage">/common/en-us/html/Instructions.jsp</Task>
<Task id="consent">consent.htm</Task>
<Task id="dropdown">dropdown.htm</Task>
<Task id="iatraceinstruct">iatraceinstruct.htm</Task>
<Task id="iatrace1" file="iatrace1.xml">/common/en-us/html/iattask6.jsp</Task>
<Task id="iatrace2" file="iatrace2.xml">/common/en-us/html/iattask6.jsp</Task>
<Task id="lastpage">lastpage.htm</Task>
<Task id="debriefing">debriefing.jsp</Task>
</Definitions>

Map

Our study map begins much like the basic example, taking participants through four tasks, startpage, consent, dropdown, and iatraceinstruct in a fixed order.

<Map>
<Task id="startpage"/>
<Task id="consent"/>
<Task id ="dropdown"/>
<Task id="iatraceinstruct" />

However, because we want to counterbalance the IATs, we need to create a branch. A branch has three parts: an id, a type, and either a select or random command. For this example, we are going to use the select command. When you wish to randomize which version of a measure participants receive, use the select = "1" option. Type is always equal to "group." The id should be a brief description that reflects the use of the branch. After the branch statement, the tasks you wish to have the file randomly choose will be placed inside. the final step is to close the branch. See below:

<Branch id="iatrace1of2" type="group" select="1">
<Task id="iatrace1" />
<Task id="iatrace2" />
</Branch>

Finally, we have the rest of the study map, which takes participants through lastpage and  then the debriefing.

<Task id="lastpage"/>
<Task id="debriefing"/>
</Map>
</Study>

Tips

  • You can choose to randomize tasks instead of (or in addition to) having sections within the study map that only selects one of two tasks. If you would wish to randomize , your opening branch would look like the following:

<Branch id="iatrace1of2" type="group" random="true">