This article applies to:
E-Prime Extensions for Tobii Pro 3.2
The CurrentObject, ComponentName and CurrentFixationDuration columns are occasionally populated in the gaze data file with stimulus information from the previous trial.
This bug typically occurs if the following happens:
- A Procedure has more than one visual E-object.
- One valid sample is obtained within the final 300 ms of the .OnsetToOnsetTime of the last visual E-Object (i.e., Slide, etc.) prior to TETStopTracking.
- A sequence of consecutive, invalid samples follows and extends into the next trial while a new visual E-Object comes onscreen.
- Valid gaze data is not obtained on the next trial for (up to) 300 ms after the first invalid sample in the sequence.
You can see if this bug exists by opening the gaze data file and verifying the CurrentObject column. In the image below, notice that the Stimulus object in the CurrentObject column exists on both the end of trial 2 (i.e., RunningSample 2) and the beginning of trial 3 (i.e., RunningSample 3).
INFO: CurrentObject definition in EET 3.2 versus older EET versions  explains how to create your own custom column in the GazeData.txt file that roughly shows what visual E-Object is onscreen when each individual eye tracker sample is taken. It also includes a sample experiment to demonstrate this method. This method does not take the validity of the surrounding gaze data samples into account. Therefore, the custom column does not exhibit the same symptoms that the default CurrentObject column does, under these rare circumstances.
If you want similiar custom columns for ComponentName and CurrentFixationDuration, you need to utilize the EET 3.1 method for saving gaze data. The script for this method is attached to INFO: SaveGazeData in E-Prime Extensions for Tobii Pro 3.1 . The 3.1 and 3.2 methods do not conflict with one another, but the main benefit of a shortened inter-trial interval that EET 3.2 method provides is lost when reintroducing the 3.1 method. When you combine both methods, two different gaze data files are also produced, a .gazedata file and a GazeData.txt file.