Post-interview guide

Appendix I:
Post-observation Interview Guide

Introduction Script

Thank you so much for your time today and allowing us to record your actions while you prepared a meal just like you would in your home. Now I would like to ask you a few follow-up questions that will focus on some of the activities you participated in while in the model kitchen.

Is it okay with you if I record your answers? The recording is confidential and will only be used to accurately capture our conversation (allowed recording y/n).

If it is okay with you, I’d like to begin this interview, which will take about 20 minutes. If no: Terminate interview.

If yes: Proceed.

Observation Follow-Up (use trigger form for context)

1. Handwashing

Did you wash your hands before you started cooking today? Can you tell me why you did/did not wash your hands?

Is that something you typically do when cooking at home? Why?

Are there times when you know to wash your hands, but you do not?

When you are in contact with food, when do you wash your hands? Why those times?

Did you wash your hands after handling the ground beef? Can you tell me why you did/did not wash your hands? What are the things that make you want to wash your hands when you are in contact with ground beef?

[If yes] Is that something you typically do when cooking at home? Why? Is this what your family/friends do? Do public health agency recommendations influence your decision to wash your hands?

Did you wash your hands after handling the brats? Can you tell me why you did/did not wash your hands? What are the things that make you want to wash your hands when you are in contact with brats?

[If yes] Is that something you typically do when cooking at home? Why?

At what other points did you wash your hands?

Has coronavirus played a role in how often or when you wash your hands? If yes, how?

2. Food Thermometer

How did you determine doneness of the burgers today?

Is that how you usually do it at home?

[If food thermometer] Can you tell me why you did that? What information were you looking for? Is there a specific temperature?

Do you have a food thermometer at home?

[If yes] Do you typically use a food thermometer when grilling at home? For which products? Why? What motivates you to use a food thermometer?

[If yes] How did you check the temperature with the food thermometer? How exactly did you insert it?

How did you determine doneness of the brats today?

Is that how you usually do it at home?

[If food thermometer] Can you tell me why you did that? [Probe: What influenced you? Is this something your family does? Is it a recommendation you saw somewhere?]

What information were you looking for? Is there a specific temperature?

3. Repackaging Leftover Ground Beef

Today we instructed you to use only half of the ground beef and to repackage the leftover ground beef. Tell me how you did this today.

Now, let’s talk about how you would prepare and store leftover ground beef at home.

How would you open the chub package and separate out the meat for use in the meal versus the meat to repackage?

When would you store the leftover ground beef: at the end of meal preparation or some other time? (Probe: after coming home from the grocery store in advance of when you would actually cook it or before meal preparation after you’ve separated what you will cook at that time)

What steps would you take to put away the ground beef you were not planning to use at that time?

What would you put the leftover ground beef in? [Probe if necessary: plastic container, plastic or freezer bag, wrap plastic wrap over the chub package, butcher paper, aluminum foil]

How would you clean up after storing the leftover ground beef?

[If not mentioned] What about washing your hands?

[If not mentioned] What about sanitizing where you unpackaged the ground beef, for example, using chlorine bleach or another sanitizer? What would you use and how would you use it? Did you sanitize before or after cleaning up? Why?

Would you label the leftover ground beef in some way? If so, how would you label it and why? If not, why not?

4. Cleaning/Sanitizing

Can raw brats spread germs to other food in your kitchen? Why? What about to other surfaces? Why do you think that?

When preparing brats at home, what do you do after you are finished? [Probe: How do you usually clean up afterward?]

[If not mentioned] What about washing your hands?

[If not mentioned] What about sanitizing, for example, using chlorine bleach or another sanitizer? What would you use and how would you use it? Do you sanitize before or after cleaning up? Why?

For the meal you prepared today, what else might spread germs?

5. Preparation of Guacamole (Subsample Only)

Tell me how you prepared the guacamole from beginning to end.

[If not mentioned] What about washing the avocados before you cut them: is this something you did or did not do?

[If yes] Why did you wash them? What were you trying to accomplish?
[If no] Why didn’t you wash them?

[If yes] How did you wash the avocados? [Probe: rinse under running water, rub with hands, scrub with a brush, soak in water]

[If yes] Did you wash your hands after washing the avocados?

FDA advises consumers to wash their avocados before peeling them. Before today, were you aware of the need to wash avocados before cutting them?

[If not mentioned] What about washing the cilantro before you chopped it: is this something you did or did not do?

[If yes] Why did you wash it? What were you trying to accomplish?

[If no] Why didn’t you wash it?

[If yes] How did you wash it? [Probe: rinse under running water, soak in water]

Have you heard of any germs that make people sick associated with avocado or cilantro? [If yes] What bacteria?

Have you ever had food poisoning?

[If yes] Can you tell me about your experience? What were the symptoms? What food do you think made you sick? Do you think you got sick from food cooked at home, or food prepared away from home?

Has a family member ever had food poisoning?

6. Questions about Intervention—Treatment Groups Only

Do you usually cook from a recipe?

Did you notice the food safety instructions in the recipes today? [If necessary: For example, the recipe stated, “Wash hands with soap and water” and “Grill burgers until internal temperature reaches 160°F on food thermometer.”]

Have you ever noticed food safety instructions like these in recipes before? Where?

[Treatment group 1—Instructions]

Did the food safety instructions influence how you prepared the meal today?

[If yes] In what way? [Probe: specific food safety instruction and food]

[If no] Why not?

Do you think reading food safety practices included in recipes would affect how you prepare food at home in the future?

[If yes] In what way? [Probe: specific food safety instruction and food]

[If no] Why not?

Is there any additional food safety instruction you would add to the recipes?

[Treatment group 2—Instructions and celebrity chef]

Before today, had you heard of J. Kenzi Lopez-Alt or the Food Lab?

[If yes] Have you prepared any of his recipes before?

Did the food safety instructions influence how you prepared the meal today?

[If yes] In what way? [Probe: specific food safety instruction and food]

[If no] Why not?

Do you think reading food safety practices included in recipes would affect how you prepare food at home in the future?

[If yes] In what way? [Probe: specific food safety instruction and food]

[If no] Why not?

Is there any additional food safety instruction you would add to the recipes?

What are your thoughts on having a celebrity chef include food safety instructions in his recipes?

Did having the food safety instructions come from a celebrity chef influence how you prepared the meal today? Why?

Do you ever search for recipes online?

[If no] Go to Section 1.7

[If yes] When searching for recipes online, do you seek out recipes from celebrity chefs?

[If yes] Which celebrity chefs?

[If yes] How much do you agree with the following statement: I follow food safety instructions because a celebrity chef endorsed them. (1 being that you strongly disagree, 7 being that you strongly agree)

7. Conclusion

We mentioned in our recruiting materials that we were interested in testing new recipes. However, the specific focus of our study is on food safety and how to prevent food poisoning. We purposely did not tell you exactly what our specific research objectives were in advance so that we could capture your behaviors in a natural way. In addition, a biological tracking agent was in the food to help us track where contamination might occur. This biological tracking agent was harmless bacteria called Escherichia coli (E. coli) K12 DH5-alpha, and it does not pose any health hazard to you. Part of its name may sound familiar because it is a harmless cousin of E. coli O157. There are hundreds of strains of E. coli, many are needed for our gut system to work correctly and are not able to make us ill. E. coli DH5-alpha doesn’t have the genes that cause disease that E. coli O157 does, which is why the second part of their names are different. This makes E. coli DH5-alpha non-pathogenic, non-toxic, and safe for humans to handle. You can request to be removed from the study at any time, and if you decide to exit the study at this point, we will destroy the recordings of your actions, and you will not be included in the data set.

We want to confirm with you now that you understand the focus of our study and that you wish to remain as a participant.

If no: Thank you so much for your time; we will remove your data from our data set and destroy any records.

If yes: Thank you for your consent.

Thank you again for your time and for your participation in our study today.

Please see the greeter on your way out to receive the $75 gift card and gift.

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