As we got close to the end of the semester, my friend Nick realized he had $1.75 left of printing money. We knew that we get a lot of money at the start of the semester and I couldn’t imagine printing enough to deplete that, so we took a look at the print history to see what had happened. It turns out you can download a CSV of all print jobs with data like time, printer name, document name, pages, color or black and white, and cost. A second CSV provided the balance history and notes on when money was added to the account. The standard computing service gives you $24. The Computer Aided Engineering Network, or CAEN, service gives you $40 more. A black and white page is $0.06 and a color page is $0.23.
Technically on the back end, you start with $24. When that is depleted, the $40 is credited to your account. The user is shown a starting point of $64 and then it counts down from there. This graph better represents what the user sees:
Clearly there was a lot more printing this semester than there was last semester. Last semester, Nick printed 606 pages. This semester? 859. The one level point this semester was the week long spring break, where nothing happened between February 24th and March 5th. So, it wasn’t that Nick hadn’t received the correct printing allotment, he really had printed so many pages that he was running out.
With all the other data, I looked at how many pages per month were printed. I used Pivot Tables to sum up the pages column and categorized it by month from the date column.
To group the pages printed by day of the week, I created a column using the formula TEXT(Date Cell,”dddd”). This takes a date and turns it into a string in the format “dddd”, which is day of the week.
Saturday blows the other days out of the water.
However, Saturday isn’t that much higher than the other days in terms of print jobs. The average pages per print job on Saturday is 8.5 compared with the next closest of 4.6 on Tuesday.
I did the same things for my own printing data.
I had some prints before the semester started in September because I sometimes did print testing at my job in IT. September was a big month because I printed out my 2 page resume 20 times. Like Nick, I’ve printed a lot more this semester than last. Two of our classes, Circuits and Aerodynamics, require a lot of printing for the homeworks.
The high levels at 10 and 11 AM are because, this semester, that is the time between two classes when we’re in the computer lab.
Monday is high because I would print out Circuits homework to start working on and also Circuits lab reports I had done over the weekend. Friday is high because of Circuits homework I would start and Aerodynamics homework which was due that day.
I do a much higher percentage of color prints because my prints are homeworks which often have graphs that need to be in color. Nick prints out more notes and sample exams for himself so he doesn’t need color as much.