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Purdue-developed Variate app, iPad-equipped labs bring chemistry testing at Purdue from the paper age to the digital age

Elliott Hall of Music is a fantastic venue to see a show, but a great place to take an exam? Not so much.

Positioned in a theater seat, hunching over a lapboard, juggling a paper test and a scannable answer sheet is unwieldy for students to say the least. Dim lighting in spots and great acoustics only exacerbate the situation.

"If somebody coughs you can hear it all over the auditorium," chemistry Professor Jonathan Rienstra-Kiracofe said. “It’s just not a good testing environment.”

Little wonder Rienstra-Kiracofe had been looking for an alternative to the mass testing of thousands of general chemistry students in Elliott almost since he arrived at Purdue.

Now, Chemistry 11500 students have had a look at what the future could hold thanks to a partnership between chemistry staff and faculty and Purdue Teaching and Learning Technologies (TLT), part of Purdue Online. That future hinges on a Purdue-developed application called Variate, which makes it possible to get the exams out of Elliott and into the digital age, no paper required.

Variate allows instructors to create math-based assessments with a friendly user interface and – since it is homegrown by Purdue – without requiring students to pay for access to a third-party platform. The multi-part test problems can include randomized variables so that each student sees a unique version of a problem.

Elliott, for all its shortcomings as a testing environment, presented another challenge in the fall semester of 2021. It wasn’t big enough for the more than 3,300 students who had to be tested, said Marybeth Miller, instructional specialist and course coordinator for general chemistry.

The solution: instead of mass testing on paper in Elliott, test students digitally over the course of a week during their normal lab periods in their iPad-equipped lab rooms at the new Chaney-Hale Hall of Science.

Because the calculation-based numerical and multiple choice conceptual questions on the exam were randomized by Variate, there was little value in a student testing later in the week conferring with a classmate who took it earlier in the week. An analysis of exam scores over the course of the testing period turned up scant evidence of illicit collaboration and nothing that couldn’t be addressed with small adjustments in the exam questions.

The system also had advantages for proctoring. Students’ iPads could be locked into the exam for the duration and monitored by the lab teaching assistants from an instructor iPad.

The experiment was a success – more than 3,300 students in 140 lab sections tested without any show-stopping issues – and the system will be used again in Chem 11500 for the fall semester of 2022, Miller said.

Surveyed after, students generally gave the new system positive reviews, 82% rated the overall test experience excellent, good or average. Approximately 64% rated it better than taking an exam in a large lecture hall or auditorium. While there was some resistance from students who were used to paper exams, 58% of them still rated the iPad version as an improvement.

Miller said support from TLT staff was a major element in the success of the project. Purdue Online’s TLT team developed Variate working in concert with faculty. In preparation for the exam cycle, TLT provided training and tested and retested the system repeatedly, then monitored the system as the exams proceeded, ready to make adjustments on the fly.

“The development team was incredible and the support we received was incredible,” Miller said. “They were kind of on call all the time. There's no way we could have done it without them.”

Besides enabling an improved test-taking experience, Rienstra-Kiracofe believes the system can enable improved student learning. With the paper tests, answers to the numerical questions were, like the conceptual questions, multiple choice. Students theoretically did calculations on the way to making the right choice. But they could always just take a guess and pick an answer. In Variate, they need to answer calculation questions with a number.

Variate can even be used to analyze student results so that problem difficulty levels can be assessed by faculty and, if needed, revisions to scoring can be made retroactively.

Being digital, Variate also facilitates the building of what can become over time a huge database of well-tested problems for exams, quizzes, homework, and practice.

“This has become, really, a tool that we will continue to use for a long time and continuously improve,” said Rienstra-Kiracofe, who worked actively with TLT to develop and refine the app.

In addition to chemistry, Purdue faculty in diverse disciplines such as engineering, genetics, economics, and Hospitality & Tourism Management are using Variate. For more information on Variate and its uses, contact

Writer: Greg Kline, 765-494-8167,