Table 2 Definitions and example instances of each code

Personal interest

Includes factors related to interests such as the discipline of geology, travel, and the outdoors

“Another thing is, I've always been interested in history. I've taken history classes, and they're full of a lot. I like that geology is like the history of the Earth, so I think that's super cool.” (Bethany)

Career opportunities

Includes factors related to the career opportunities associated with the discipline

“And geology just seemed the most applicable. And it also seems like if worse came to worse and I needed to get an entry level job that was not terribly paying, that would also be a fallback. It felt like the safest option as a fall back plan too.” (Janice)

Department

Includes factors related to aspects of the geology department, geology classes and field experiences, and/or geology faculty

“The professors really. You know it is 240 is known to be the make-or-break for geology majors. The professor, [professor name], just really showed us what geology is. It's experiential learning, learning by experience instead of just lecturing, which I really, really liked. It's really nice to not be in a class where you can learn on your own. I feel like it helps you learn better. I took a microbiology class. I was in a lecture with 180 people. It was awful. The professors didn't know you but the geology program they all know you. They build a relationship with you. That really kind of pushed me towards geology instead of biomed.” (Samantha)

Influenced by others

Includes factors related to encouragement by family, friends, teachers, and/or non-major professors

“One of my really good friend's dad, he actually went to [university name] and did his master's here as well. And then he has this water company and they dig wells. And the whole time, my whole life I've always been like, ‘No one really knew what Marvin did.’ It's not like none of us kids, we were like, ‘What is geology? There is a well.’ And even his son would be like, ‘He digs wells.’ You can't have a career doing that. Right?’ So he was a pretty big influence and he was always so knowledgeable too.” (Elisabeth)

Personal values

Includes factors related to values such as helping others, the environment, and persistence

“I really appreciate that what you do matters and I always try to tie it into something, well like this is an issue that needs fixing, and you are the only people that understand the issue, so you need to come up with this solution for it. I guess there is a lot of responsibility that comes with that too and it's on a level I didn't expect to have so early. I really appreciate not only am I doing something that I like I am doing it with people that I trust and we are trying to work on things that should benefit more people. Even if we can't explain to them that what we are doing is important, they will still benefit.” (Celeste)

Course experiences

Includes factors related to course experience that occurred before a student declared as a geology major

“My high school year I took a geology course. I always wanted to be a doctor at first. I came in with biomed and then before I actually started at [university name], which I did a dual major of biomed and geology. I was still taking both of those classes kind of getting a feel what I wanted to take. In high school I took a geology class and I fell in love with it. I was like, I really like this. I want to explore this more.” (Samantha)