Scratch to Succeed

By Larry Trincia
Science Department
Delaware Technical Community College
George Campus

It is a challenge for me to incorporate some of the educational tools available into my science classes. Most of my physics classes involve a lot of problem solving. Solving problems, many problems, leads to good outcomes for students that do them.

On the other hand, much of physics is conceptual. One device I have used many times in several classes of my classes for learning physics concepts is the Immediate Feedback Assessment Tool (IF-AT).

I have received unsolicited positive feedback from my students with this activity. That’s great. But that alone is not why I like it. I believe it is a great way for students to learn.

IF-AT replaces the traditional multiple choice test.   Students, working in small groups, read a multiple-choice question on a test.   They talk about it together and choose one of the answers on a card that is covered with a solid colored covering, like a scratch-off lotto ticket. They select an answer by scraping off the covering, which reveals whether the answer is correct or incorrect.

A star beneath the covering means a correct answer. Absence of a star means they get to try again with partial credit. The instructor defines the relative points for each successive answer.

One positive aspect of IF-AT is that it gets students talking to each other. Students seem to have less inhibition talking to their classmates than to the teacher.

Another benefit is better retention of information. Epstein Educational Enterprises, the developer of IF-AT, maintains that studies show that immediate feedback enhances learning.   They say the last correct response on a test is the one students retain.   My classroom experience bears this out even though I initially dismissed their claims as marketing hype.   At the end of the activity, students have a test with all the correct answers they can study from.

What I have noticed is that grades are typically higher on these tests. Students tend to focus less on the grade than on the content of the test.

The down side of IF-AT is it increases the preparation time for the instructor. The IF-AT cards are pre-programmed. That means that tests have to accommodate the pre-programmed answers on the IF-AT cards.   IF-AT cards are purchased in batches, each of which has a unique key that corresponds to the programmed answers.   Once you run out of a batch, you have to modify your tests to conform to the next key. Not much work, but work.

Despite this drawback, I find that IF-AT is worth the time. They are perfect for questions that require critical thought. Here is an example of such a question from one of my quizzes in ultrasound physics:

As you perform a superficial Doppler study with a high frequency transducer, you see some grayish haze and scintillation. You notice there is a bone below your gate just about the same distance from your gate as your gate is from your transducer face.   An experienced technician tells you that you do, in fact, have an artifact that is sometimes referred to as “herbies”. What can you do to get rid of the artifact?

A) Increase your pulse repetition frequency

B) Use HPRF

C) Use a different view which increases the depth of your gate

D) Use a different compression algorithm

This question requires the student to evaluate different options, which tests their understanding of a specific type of artifact encountered in ultrasound. Students have to vocalize and compare the different techniques presented and come to a consensus on the answer. This type of situation is the type of decision that mimics one they might encounter in their profession.

P.S. – If you think you know the answer, leave it in the comments!

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