CHC9012 | National Taiwan Normal University
This week, we will discuss how to set the parameters of a template to obtain a more simple and yet more powerful script.
By the end of this week: You will have the script of your very final experiment ready!
How to optimize your script:
A brief summary of the essential elements:
Template(...): Used to introduce a trial template.Sequence(...): Used to control the order of the different parts of the experiment.randomize(...): Used to present the trials using a random order.newVar(...): Used to create a new variable.getX(...): Used to obtained the content given by the participants.getVar(...): Used to obtain the content of an element stored in a variable.So far, we created an experiment following this structure:
flowchart LR A([👋 Welcome page]) ==> B([🛠️ Practice trials]) B ==> C([🧪 Experimental trials]) C ==> D([🏁 Goodbye page]) style A fill:#f8f9fa,stroke:#3498db,stroke-width:2px style B fill:#f8f9fa,stroke:#2ecc71,stroke-width:2px style C fill:#f8f9fa,stroke:#e74c3c,stroke-width:2px style D fill:#f8f9fa,stroke:#95a5a6,stroke-width:2px
But more precisely, it looks like that, with multiple trials:
flowchart LR
A([👋 Welcome page]) ==> B([🛠️ Practice trials])
subgraph Exp [🧪 Experimental trials]
C1([Trial 1]) --> C2([Trial 2]) --> C3([Trial 3]) --> C4([Trial 4]) -.-> C5([Last Trial])
end
B ==> C1
C5 ==> D([🏁 Goodbye page])
style A fill:#f8f9fa,stroke:#3498db,stroke-width:2px
style B fill:#f8f9fa,stroke:#2ecc71,stroke-width:2px
style D fill:#f8f9fa,stroke:#95a5a6,stroke-width:2px
style C1 fill:#f8f9fa,stroke:#e74c3c,stroke-width:2px
style C5 fill:#f8f9fa,stroke:#e74c3c,stroke-width:2px
style Exp fill:none,stroke:#e74c3c,stroke-width:2px,stroke-dasharray: 5 5
Instead of typing the trials in the script, we create a table where we can list them.
| ItemNo | Sentence | Condition |
|---|---|---|
| 1 | This is the first sentence | Grammatical |
| 2 | This is the second sentence | Grammatical |
| … | … | … |
Note
Create material.csv in the PCIbex Resources section.
Paste the following inside the new file named material.csv in PCIbex:
ItemNo,Sentence,Condition
1,This is the first sentence,Grammatical
2,This is the second sentence,Grammatical
3,This is the third sentence,Grammatical
4,This is the fourth sentence,Grammatical
5,This are the fifth sentence,Ungrammatical
6,This are the sixth sentence,Ungrammatical
7,This are the seventh sentence,Ungrammatical
8,This are the eighth sentence,UngrammaticalDone!
We must specify that we are dealing with a template using the Template() function.
/// 3. Experimental trials
+ Template("material.csv", row =>
newTrial("Experiment",
- newText("FirstSentence", "This is another grammatical sentence")
+ newText("Sentence", row.Sentence)
.print()
.center()
.log()
,
newScale("Scale", "1", "2", "3", "4", "5", "6", "7")
.labelsPosition("bottom")
.before(newText("Not acceptable"))
.after(newText("Acceptable"))
.print()
.center()
.wait()
.log()
)
+ ) // This is the closing parenthesis corresponding to `Template()`
- newTrial("Experiment",
- newText("SecondSentence", "This sentence not is grammatical")
- .print()
- .center()
- ,
- newScale("Scale", "1", "2", "3", "4", "5", "6", "7")
- .labelsPosition("bottom")
- .before(newText("Not acceptable"))
- .after(newText("Acceptable"))
- .print()
- .center()
- .wait()
- )Done!
To get more information in the results file (ItemNo, Sentence, Condition), we add .log() to the template:
/// 3. Experimental trials
Template("material.csv", row =>
newTrial("Experiment",
newText("Sentence", row.Sentence)
.print()
.center()
- .log() // Since we know it does not work, let's delete it
,
newScale("Scale", "1", "2", "3", "4", "5", "6", "7")
.labelsPosition("bottom")
.before(newText("Not acceptable"))
.after(newText("Acceptable"))
.print()
.center()
.wait()
.log()
)
+ .log("ItemNo", row.ItemNo)
+ .log("Sentence", row.Sentence)
+ .log("Condition", row.Condition)
)Done!
This is a a two-step process to store such information in the results file:
flowchart LR A(["👋 Welcome page <br> <b>Define the variable</b>"]) ==> B(["🧪 Experimental trials <br> <b>Log the data</b>"]) style A fill:#f8f9fa,stroke:#3498db,stroke-width:2px style B fill:#f8f9fa,stroke:#2ecc71,stroke-width:2px
Note
👋 Welcome page!newVar() element to create a new variable, and then (2) the getTextInput() and getDropDown() to tell PCIbex what content to keep in memory!Let’s look at the code:
// 1.2 Background questionnaire
newTrial("Background information",
newText("We will ask you some questions about your background. Please feel free to skip some questions if you do not wish to answer.")
.print()
.center()
,
newText("Your age:")
.print()
.center()
,
newTextInput("Age")
.print()
.center()
.log("final")
,
newText("Your highest degree:")
.print()
.center()
,
newDropDown("Degree", "Please select one option")
.add("Elementary school", "Junior high school", "Senior high school", "BA", "MA", "Ph.D.")
.print()
.center()
.log()
,
newButton("Continue")
.center()
.print()
.wait()
+ ,
+ newVar("Age")
+ .global()
+ .set(getTextInput("Age"))
+ ,
+ newVar("Degree")
+ .global()
+ .set(getDropDown("Degree"))
)Done!
Note
Now that you created the variable and that they are kept in memory, we can store them in the results file using the .log() command. But notice the use of getVar()!
/// 3. Experimental trials
Template("material.csv", row =>
newTrial("Experiment",
newText("Sentence", row.Sentence)
.print()
.center()
.log()
,
newScale("Scale", "1", "2", "3", "4", "5", "6", "7")
.labelsPosition("bottom")
.before(newText("Not acceptable"))
.after(newText("Acceptable"))
.print()
.center()
.wait()
.log()
)
.log("ItemNo", row.ItemNo)
.log("Condition", row.Condition)
+ .log("Age", getVar("Age"))
+ .log("Degree", getVar("Degree"))
)Done!
We can specify the sequence of the whole experiment at the beginning:
Sequence("Welcome page", "Background information", "Instructions",
"AnnouncementPractice", "Practice", "AnnouncementEndPractice",
randomize("Experiment"),
"Send", "Goodbye")Note
newTrial("name") command!randomize() command to present the trials in a random order.Note
Example: For some reasons, you want Participant 1 to read half of the sentences, Participant 2 the other half, Participant 3 the same as Participant 1, Participant 4 the same as Participant 2, etc.
How to do that with PCIbex?
Add a group column to your material table for counterbalancing.
| ItemNo | Sentence | Condition | group |
|---|---|---|---|
| 1 | Sentence 1 | Grammatical | A |
| 2 | Sentence 2 | Grammatical | B |
material.csv fileItemNo,Sentence,Condition,group
1,This is the first sentence,Grammatical,A
2,This is the second sentence,Grammatical,A
3,This is the third sentence,Grammatical,B
4,This is the fourth sentence,Grammatical,B
5,This are the fifth sentence,Ungrammatical,A
6,This are the sixth sentence,Ungrammatical,A
7,This are the seventh sentence,Ungrammatical,B
8,This are the eighth sentence,Ungrammatical,BAdd a group column to your material table for counterbalancing.
| ItemNo | Sentence | Condition | group |
|---|---|---|---|
| 1 | Sentence 1 | Grammatical | A |
| 2 | Sentence 2 | Grammatical | B |
Don’t forget to use the log() element to keep track of which list the participants were assigned to!
Assignment
You can even start preparing your own experiment!