This article is one of a series of Experiments meant to teach students about how science is done, from generating a hypothesis to designing an experiment to analyzing the results with statistics. You can repeat the steps here and compare your results — or use this as inspiration to design your own experiment.
A scientific experiment can be as close as your kitchen. But when doing science that will involve people, you’ll need to be careful about how you test your tasty creations in ways that protect those volunteers.
Welcome back to Cookie Science! In a series of blog posts, I am demonstrating how to design an experiment and carry it out. We’ll go over how to collect and analyze data and much more. My goal is to create a cookie for my friend Natalie. She has celiac disease, a disorder where her immune system attacks the small intestine after she eats gluten. Gluten is a protein found in wheat, and wheat is found in cookies. I wanted to make a cookie that Natalie could safely enjoy.
I compared several recipes for regular chocolate chip cookies and for gluten-free alternatives. I came up with a hypothesis. I postulated that substituting gluten-free flour alone will not give me a cookie as delicious as my original. To test this, I will have to make some cookies using the original recipe. They will be my control, the cookies against which all others are compared. I will also have to make cookies using the same recipe, with only one change — gluten-free flour.
But to compare the tastiness of my cookies, people must eat them. Afterward, they’ll need to take a survey to tell me how much they like each cookie and why. This is where a scientist has to think about ethics. Ethics in research is about being honest, fair and not harming people who participate.
It would be wrong for me to test my cookies on people without asking them if they wanted to be part of an experiment. My taste testers need to choose whether they want to take part. And, of course, it would be wrong to feed these people something that might harm them. It might seem silly to think about cookies causing harm. But what if someone has celiac disease, like my friend? They could get extremely sick if they receive the control cookie containing wheat gluten. Or what if someone is allergic to another of the ingredients that I use? Throughout my testing, it’s very important for me to make sure that no one gets hurt. So I need to inform everyone about the ingredients I’m using so that they can make an informed decision about whether to participate.
To ensure that my experiment is as fair to my cookie tasters as possible, I wrote up a protocol. This plan of action details exactly what I want to do, how many cookies people would have to eat to reliably judge their flavor and taste, and what questions the survey should ask.
I also created a form for each participant to sign. It asks each to give his or her informed consent before taking part. This form lists all cookie ingredients. If a would-be participant sees an ingredient that could make them sick, they now know not to take part. The consent form also tells the participants what they will be asked to do in the study — and that they can back out of the study at any time. This makes sure that my cookie tasters are eating my cookies because they want to, not because they feel forced.
I then submitted my protocol and consent form to a panel of three scientists and educators. I wanted to make sure that people unrelated to the experimentation agreed that it looked safe and ethical. Such a panel is known as an Institutional Review Board, or IRB. An IRB is recruited to look for any risks associated with a study that involves people. They will determine if the study poses too high a risk of someone being harmed. The IRB also scouts for signs that people might be forced into the study or to do anything that might be unfair.
The panel I sent my protocol to is a group that evaluates all studies involving people that are conducted by students taking part in the Intel International Science and Engineering Fair. Three people looked over my study. One of them asked questions about what I wanted to do. Another gave me tips to make my consent form better. In the end, I got the board’s approval to conduct my experiment.
If you want to conduct a scientific experiment using people — even one that just asks people questions — it is important to make sure those people are treated well and fairly. And this is especially true if the findings might be used in a local science fair. If you plant tests involving people, develop a protocol and then try to find an IRB panel to review it. There are IRB panels at every major university. You also can ask local scientists to help you design a procedure that will be scientifically accurate and that will make sure all participants will be safe and treated fairly.
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celiac disease (or coeliac disease in the United Kingdom) A disorder in which the immune system attacks the small intestine after it encounters foods containing gluten, a wheat protein compound. People with this disease suffer from stomach pain, constipation, diarrhea and a constant feeling of fatigue. They must avoid gluten-containing products like bread, cake and cookies.
ethics A code of conduct for how people interact with others and their environment. To be ethical, people should treat others fairly, avoid cheating or dishonesty in any form and avoid taking or using more than their fair share of resources (avoiding greediness). Ethical behavior also would not put others at risk without alerting people to the dangers beforehand and having them choose to accept the potential risks.
gluten A pair of proteins — gliadin and glutenin — joined together and found in wheat, rye, spelt and barley. The bound proteins give bread, cake and cookie doughs their elasticity and chewiness. Some people may not be able to comfortably tolerate gluten, however, because of a gluten allergy or celiac disease.
hypothesis A proposed explanation for a phenomenon. In science, a hypothesis is an idea that hasn’t yet been rigorously tested. Once a hypothesis has been extensively tested and is generally accepted to be the accurate explanation for an observation, it becomes a scientific theory.
Institutional Review Board A panel of experts that reviews experiments that would involve people. The board does its best to ensure that when people will be test subjects, they will be treated fairly and not exposed to undue harm (unless they were informed ahead of time and they have been given the opportunity to opt out).
palatable An adjective for something that is pleasant, appetizing and tastes good.
protocol (in science) A written procedure to describe how an experiment will be conducted. Protocols are written before an experiment is performed and are used to make sure that the experiment meets standards for fairness and good practice. Protocols also allow other people to attempt the same experiment and see if they can replicate previous results.