Hello,
You have four lines per trial because, by default, each PennController trial reports one line for when it starts and one line for when it ends. Then your trials use the log command on an Image element and on a Scale element, which will report two more lines per trial, one for each: one line reports when the Image element was printed onto the page, the other line reports what value was selected on the scale + when the selection occurred. This way, if you need to calculate the time difference between any pair of those four events, you have the option to do so. If all you care about is the value that was selected on the scale, you can just subset the table to those rows that report about the Scale element
This page of the advanced tutorial illustrates how one can parse the data in R. In particular, read.pcibex will automatically name the table’s columns using the comment lines from the results file (the line starting with #) and the command filter can be used to subset to certain rows only, for example filter(PennElementName == "side-by-side" | PennElementName == "selection") %>% keeps only the rows that correspond to the elements named “side-by-side” or “selection” in the tutorial’s study
Jeremy