Lab 2 – Matrix Rotation
In this lab, you’ll run through a Matrix rotation task as well as 4 friends, and analyze the results.
Materials
1. Computer running Pebl
2. The Learning & Cognition Pebl files, which you can download using the links below.
3. The Matrix Rotation R analysis file, which you will download below.
4. You (to take the experiment).
Procedure
1. Make sure you have PeBL installed – see the first section of this lab manual.
2. Launch the PEBL graphical interface.
3. In the PEBL Launcher, add “matrixrotation.pbl” (from the PEBL library, batterymatrixrotation directory) to your Experiment Chain
4. Set a participant code for the participant you are running.
5. Launch the chain.
Run at least 5 individuals in this task. Once your data has been collected, you’ll find the data in the ‘data’ directory inside batterymatrixrotation. One file will be created for each participant. Opening the file in Notepad or Excel will allow you to view the data collected.
Now that you have your data file open, download the Matrix Rotation R Script and open it. It’s a pretty simple scriipt. On the 4th line, you’ll need to put in the sequence of correct/incorrect data from your data file. The data file has this in column “CB” at the far right side of the data file.
= c(0,1,1,0,1,1,1,0,0,1,0,1,1,0,1,1,1,1,1,1)
Run the t-test for each participant you have. Below is sample output of a t-test.
Paired t-test
data: x2$`1` and x2$`2`
t = -1.8091, df = 9, p-value = 0.1039
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
-0.9001818 0.1001818
sample estimates:
mean of the differences
-0.4
If you look at the p-value, you see it’s above 0.05. This means that this participant did not do any different on the second ten trials compared to the first. If the p-value had been below 0.05, it would mean that they did do better. If they did better, you could then look at the mean of the differences line. If that line is positive, it means that they got worse on the second ten trials. If it’s negative, it means they got better.
So check the p-value first, then if it’s below 0.05, check the mean of the differences. In your lab report, talk about how each of your participants did, including yourself. Then talk about where you might see matrix rotation tasks in the real world. A minimum of 2 pages, single-spaced, is expected, including figures, for the body of your Lab Reports. Make sure you are using APA formatting, including a cover page, and final reference page (not included in your page count), and writing in your own words.