Teaching Hub

Scan and Deliver! Personalized Feedback in Large Classes

by Marco Bonizzoni and Diana Leung, Department of Chemistry

Organic chemistry is a surprisingly visual discipline. Molecules, the fundamental entities of chemistry, exist as 3D objects whose shapes often profoundly influence their properties, so students must learn the visual language of the discipline, which attempts to convey the nature of these three-dimensional objects through two-dimensional drawings. When it comes to testing, students answer open-ended questions in handwritten free form. We both encourage our students to learn from their mistakes, from the hand-graded test and the written feedback provided; we both provide students with our detailed answer keys as well. However, this process requires that the entire graded exam be returned to students.

The Problem

We both became frustrated with the process of returning the physical graded exams in our large enrollment classes (150-320 students), because it typically became a messy and time-consuming chore. It was never very effective, either: even after multiple attempts and emails, a handful of exams would simply never be picked up. The problem with returning the physical exams was compounded by the fact that we both give students the opportunity to request a regrade (mistakes happen, and we must deal with them!). Once exams have been returned, however, unscrupulous students may “fix” their answers, and then request a regrade. This obvious case of misconduct is hard to detect without a copy of the original exam.

We came up with the idea of scanning and returning the exams electronically: all students would receive their graded exam back; appropriate delivery would safeguard their privacy; and the integrity of the graded exams would be ensured. As an added bonus, retaining a copy of the graded exams would be helpful, for instance, to use during office hours, or to peruse for common mistakes and tailor upcoming lectures. However, scanning each individual exam by hand would be entirely impractical. We needed a solution to automate the process so it could be run in a single batch, and yet retain the individual files.

Diana and I worked together to implement such a method, using available hardware and inexpensive software. This method, inspired also by an article in the Journal of Chemical Education describing a similar problem at the University of Georgia, is now in its fourth semester of use. It ensures that all students have access to their graded tests and can learn from them, that we retain copies of those exams for future reference, and that students cannot modify their answers to achieve a higher score fraudulently.

We use individualized barcode labels encoding each students’ information, common office copier/scanner machines to scan the exams in large batches, barcode reading software to chop up the batch scans into individual files, and automated mailing lists to deliver the exams to each student.











Ahead of each exam, we generate adhesive labels from our class rosters using Microsoft Word’s “Mailings” features; on each label, we print the student’s name, and a barcode encoding their CWID. We bring these labels to the exam. Students collect their own label and affix it to their exam as they turn it in. Exams are then hand-graded as usual.


Instead of returning them to students during the next class meeting, however, we remove the stapled corners and feed the stacks of exams to our office copier-scanner through the automatic document feeder, obtaining one large PDF containing all exams. We then use the software A-PDF Split and Scan to split this master file into individual exams: as it goes through the PDF file, the software seeks the barcodes and splits the large file into individual PDFs each time one is encountered, thus generating a series of files, each containing a single exam. The individual files are named with the corresponding student’s CWID, read from the barcode label.


We automatically generate individualized emails to each student including their graded exam as an attachment. We use Mozilla Thunderbird with the MailMerge extension (Outlook would work as well). These emails can be personalized; for instance, we urge poorly performing students to come to office hours to go over their exam. We also recognize excellent performance by adding a few words of congratulation in the email.


We encountered only one significant snag: when the individual PDF files were sent to students as email attachments, some mobile devices only showed the first page of these attachments in preview mode, so students thought either that they had received a corrupted PDF, or that only the first page was actually included. We now issue a warning about this issue in the email and mention this in class.


We are very pleased with the results from our method so far. Optimizing each step took some time but, with all the tools in place, it now takes very little to repeat the process. Anecdotally, we have also received very positive feedback from our students on their experience. As an added bonus, we have both seen a decline in regrade requests as well. Finally, the stored exams have proven very useful to evaluate class proficiency on a specific topic, since it is straightforward to extract a specific portion from all exam automatically. Such compilations of the class performance give the instructor unprecedented insight into the performance of the whole class, which was hard to attain when the instructor only ever saw a relatively small portion of the exam while grading it, if any.


In the future, we would like to move away from email as a delivery method to reduce FERPA concerns; a better option would be selective delivery through Blackboard, but such functionality is currently not available. We would be happy to share further details, or to help anybody that might be interested in using this process.

See also Details and Procedures: Returning Hand-Graded Exams Electronically and Managing hand-graded exams in large enrollment classes (pdf).

Dr. Marco Bonizzoni is an Assistant Professor in the Department of Chemistry at UA. At the undergraduate level, he primarily teaches classes in the organic chemistry series. These are large-enrollment classes (150-320 students) taken by sophomore students with a wide variety of backgrounds in the STEM fields, biology, engineering, and chemistry being the most common.

Dr. Diana Leung is an Assistant Professor (NTRC) in the same department. She teaches general chemistry, organic chemistry, and general/organic/biological chemistry for nursing students, together with the attendant laboratory courses. All of these are large enrollment classes, but typically only those in the organic chemistry series include hand-graded exams.