Although the exercises did not affect how students viewed
the nutritional value of fast food, they may have had an impact
on students’ nutritional choices. Only three of the 18 students
who responded said the exercises had no effect on their interest
in eating fast food, while the remaining 15 responded that the
exercise made them less interested in eating fast food. We infer that
students found the act of disassembling the items and seeing them
grow mold objectionable.
These exercises were impactful for our students in three ways. First,
investigating a popular online claim was an engaging way to practice
development and differentiation of hypotheses and predictions and
to improve quantitative literacy. Students often confuse hypotheses
and predictions (McPherson, 2001). Roughly 75% of the students
in our college introductory course began with difficulties in differentiating questions, hypotheses, and predictions and in setting up and
completing a spreadsheet. Since these exercises were part of a course
that primarily surveyed biodiversity, they were the only opportunities for our students to learn about hypotheses and predictions.
The experiment also served as an opportunity to improve skills in
experimental design, although we did not measure that explicitly.
Our students found that, contrary to their initial conceptions, some
fast-food items could grow mold. They were able to see that a famil-
iar online claim was not true and that other information they find
online might not be accurate.
Second, the exercises paired with a standard teaching unit
effectively assisted students with learning about fungi. Planning to
inoculate fast-food items that some frequently consumed gave the
students a greater stake in the exercise than they typically would
have following a lab manual. The increased interest was evident
when we tested our students for content knowledge after the exercises. We were able to assess effectiveness by comparing student
performance over multiple semesters with and without the exercises; quiz grades increased by >10% starting in the year (2014)
we began using this exercise.
Third, these exercises allowed students to share and consider
their nutritional practices, especially their consumption of fast food.
Examination of dietary choices is especially important as students
begin college, when many are in control of their choices for the first
time and may make choices that harm their long-term health
(Stockton & Baker, 2013). We gained interesting information
about what students ate, and they were able to discuss their choices
with their classmates and with us. Many of our students declared
interest in a change from potentially harmful eating habits after
Our students tested the online claim that fast food does not
decompose only by observing and measuring mold growth. They
were able to determine what types of fast food allowed mold growth
and came up with explanations for their observations. The claim can
be further tested; for instance, students could weigh items over time
and test for growth of other decomposers besides fungi. Swabbing
burgers and attempting to culture and identify decomposing bacteria
is an extension that also allows students to discuss food safety, which
is currently a critical issue (Centers for Disease Control and Prevention, 2018).
In conclusion, there are essentially unlimited opportunities to
examine online claims in lab courses as more online claims are made
and students share information they read online. We recommend
that high school and college instructors seek out their own online
stories and develop ways to test them or seek original information
in peer-reviewed scientific literature. Such activities can be effective
and engaging learning experiences.
We thank Tom Diggs, Swapna Bhat, and anonymous reviewers for
constructive comments on the manuscript, and we thank all the
students who have participated in this project since 2014.
Andrews, D. (2014). Nearly 500 ways to make a yoga mat sandwich. The
Environmental Working Group. https://www.ewg.org/research/nearly-
Barbacariu, C.L. (2014). Parents’ refusal to vaccinate their children: an
increasing social phenomenon which threatens public health. Procedia
– Social and Behavioral Sciences, 149, 84–91.
Figure 4. Mean (± SE) student ratings of perceived nutritional
value on a 1–10 scale (10 = most nutritious) of fast food overall
(A) and of fast-food hamburgers (B). Group 1 inoculated
hamburgers, while Group 2 inoculated bread.