This assignment called to manipulate tables and dataframes, including reading them from a file and writing them to a file. The plyr package makes these processes easy with ddply, especially when used in combination with grepl.
The only confusion I faced with this assignment was the last step, which required us to write the filtered dataset and convert it to a CSV file. While I was able to use file.choose() to get the file path and convert it to a CSV, I found it easier to skip this step and write the CSV directly from the dataframe with write.csv(). This may be a misunderstanding of the assignment directions because I did not find the need to use subset() as indicated in the assignment hint.
Output File 1 - Student Averages.txt
Output File 2 - Students (containing "i") Averages.txt
Output File 3 - Students (containing "i") Averages.csv