In this tutorial you’ll program a bit yourself. We’ll take baby steps, don’t worry. Every time you see the symbol, it means you have to start typing yourself at that point, before you go on reading. At the end of the tutorial you will have made your first experiment with Inquisit.
First some practical information. You start Inquisit from the Start menu (All programs, Inquisit 4). The experiment you create will be written in a file called a script. A script file has the extension .exp. Double-clicking such a file will automatically start Inquisit and run the experiment. If you want to edit the file, open it from within Inquisit. If you want to try out your experiment, go to Experiment in the menu, and click Run. To interrupt an experiment, press Ctrl + Q.
When running the experiment, Inquisit will automatically create a data file with the same name, but using the .dat extension containing the responses and reaction times of participants in your experiment.
So now you loaded Inquisit and see an empty white window in front of you. How do you get from here to a working experiment? First you will need to make a few decisions. The most important one is of course deciding on the experimental paradigm, and then you start programming the paradigm from the bottom up. Let’s say you want to know whether participants have an implicit preference for flowers versus spiders. One possible experimental paradigm would be an IAT with words and names (although in this case pictures might work better, but to keep things easy, we’ll stick to spider and flower names). The next steps are the bottom-up decisions. Think about the possible answers you could give at each step:
- Stimuli: What kind of stimuli would you need? Which categories? Think of some examples.
- Trials: What kind of trials do you need? What does a trial look like? What is the order and timing of the stimuli? What kind of responses can a participant give? When is a response the right one? What happens if the participant responds incorrectly?
- Blocks: How are the trials ordered in blocks? What are the instructions for each block?
- Experiment: How are the blocks ordered? How does this depend on conditions? How are conditions selected?
On each level of the bottom-up thought process there is an Inquisit counterpart that you need to program. I recommend that when you program, you start out programming the experiment in this same bottom-up order.
So let’s decide on some stimuli. For the IAT we have in mind, we need four different categories of stimuli: spider names, flower names, positive words, and negative words. We will now actually program these stimuli in Inquisit. To tell Inquisit that we have some negative words that form a category of stimuli enter the following text in the open window:
<item negative> /1 = “tragic” /2 = “horrible” /3 = “awful” </item>
Take a closer look at the text you just entered. The first and last lines are called tags. The first line is an open-tag that tells Inquisit that the lines below, until the close-tag on the last line are items to be used as stimuli. The item part on the first line is called the element. There are multiple types of elements, for each of the different bottom-up steps. We will come across many of them. In the open-tag the second part is a name which you will use in the rest of the script to refer to the information contained in this specific tag (note: these names are case-sensitive). The close-tag always repeats the element, in this case item, but with a slash before it, marking it a close-tag. The lines between the open-tag and close-tag contain the actual stimuli. Every line within tags always start with a slash, indicating so-called attributes. Different elements have different attributes. You will see many of them as we go. In the case of item elements, the attributes are actually stimulus numbers, with the words between the quotations marks being the actual stimulus. In this case the stimuli are plain text, but here you could also put filenames of pictures or sound files within the quotation marks.
Of course, three stimuli are not enough to fill an entire IAT. Go ahead and complete the list until you have ten different negative words. Then, make three more item lists, one for positive words, one for spider names and one for flower names. For the continuity of this manual, it’s important that you call them negative, positive, spider, and flower. Remember, these are the names you add as second part to the open-tag, and which will be used in the entire script to refer to these specific stimuli.
A note on structuring your script: It does not matter in what order you place the elements of the script, as long as all elements that you need are in the script, and every element has its own start-tag and end-tag. When you run the experiment, Inquisit will read through your script, ch