PhD students as RA(for tuition+stipend) only vs RA (for tuition)+TA(for stipend)

[kerprof]

I have started out recently (1 year back) in a new institution as Associate Professor. I am required to go for tenure application in Fall 2022.

Due to COVID, I  have not got the opportunity to do full-fledged work with PhD students yet.

I am thinking of the pros and cons of taking fewer PhD students vs. many PhD students as I am in the process of giving offers to potential PhD students, who will be starting in Summer/Fall  2021.

Is it a good idea to have fewer PhD students concentrate on as being RA only (with these PhD students supported (tuition + stipend) by my grants and start up fund)  OR is to a good idea to have many PhD students supported as RA (for tuition though my grants + start up fund) and supported as TA (for stipend doing work for Dept).

Since these PhD students are just starting they also need to take course work rather than dissertation. Also students supported by grants (rather than start up funds) would need to do perform work related to grant.

Please advise.

[fizzycist]

In every dept I am familiar with, if a student is on TA then dept pays tuition. How is it even legal for you to pay student tuition from a grant yet they spend their available working time as a TA (and thus not on the research supported by the grant)?

Anyway, regarding TA vs RA, I usually let students TA in their first two semesters and then support them as full RA starting their first summer until graduation.

[research_prof]

If several students have the skills that you need, get them all. Offer RAs to the most promising ones, then TAs to the rest. I would first get the students and worry about the rest later on. Again assuming that the quality of students is acceptable.

[polly_mer]

In my fields, being a TA is viewed as a distraction from research, especially when still taking courses oneself. 

Being admitted with a TA offer means the faculty see you as cheap labor supporting intro courses and good applicants will decline those offers in favor of research funding, if they have good mentoring regarding grad school.

[mleok]

In every dept I am familiar with, if a student is on TA then dept pays tuition. How is it even legal for you to pay student tuition from a grant yet they spend their available working time as a TA (and thus not on the research supported by the grant)?

Anyway, regarding TA vs RA, I usually let students TA in their first two semesters and then support them as full RA starting their first summer until graduation.

This, a RA is supposed to pay for a student to work on a project, it can't be used to pay tuition without a correspond time commitment to the project. At my institution, my students often do a 25% GTA which covers the stipend and tuition, and a 24.99% GRA which covers an additional stipend.

[kerprof]

In every dept I am familiar with, if a student is on TA then dept pays tuition. How is it even legal for you to pay student tuition from a grant yet they spend their available working time as a TA (and thus not on the research supported by the grant)?

Anyway, regarding TA vs RA, I usually let students TA in their first two semesters and then support them as full RA starting their first summer until graduation.

This, a RA is supposed to pay for a student to work on a project, it can%u2019t be used to pay tuition without a correspond time commitment to the project. At my institution, my students often do a 25% GTA which covers the stipend and tuition, and a 24.99% GRA which covers an additional stipend.

How many hours per week student work on teaching assistantship duties and how many hours per week, the student will work on research assistantship...

[mleok]

In every dept I am familiar with, if a student is on TA then dept pays tuition. How is it even legal for you to pay student tuition from a grant yet they spend their available working time as a TA (and thus not on the research supported by the grant)?

Anyway, regarding TA vs RA, I usually let students TA in their first two semesters and then support them as full RA starting their first summer until graduation.

This, a RA is supposed to pay for a student to work on a project, it can%u2019t be used to pay tuition without a correspond time commitment to the project. At my institution, my students often do a 25% GTA which covers the stipend and tuition, and a 24.99% GRA which covers an additional stipend.

How many hours per week student work on teaching assistantship duties and how many hours per week, the student will work on research assistantship...

For us, a full time appointment is 40 hours per week, so 25% GTA is 10 hours per week, and a 24.99% GRA is a hair shy of 10 hours per week.

[fizzycist]

In every dept I am familiar with, if a student is on TA then dept pays tuition. How is it even legal for you to pay student tuition from a grant yet they spend their available working time as a TA (and thus not on the research supported by the grant)?

Anyway, regarding TA vs RA, I usually let students TA in their first two semesters and then support them as full RA starting their first summer until graduation.

This, a RA is supposed to pay for a student to work on a project, it can%u2019t be used to pay tuition without a correspond time commitment to the project. At my institution, my students often do a 25% GTA which covers the stipend and tuition, and a 24.99% GRA which covers an additional stipend.

How many hours per week student work on teaching assistantship duties and how many hours per week, the student will work on research assistantship...

Kerprof, I think you might want to sit down with some more experienced faculty and some experienced admins in your department and ask them more about the entire grad student support process. It seems you may need an orientation about how it all works.

Of course it is also possible you already know and I have misinterpreted your questions (if so, sorry!)

[born_a_prof]

In my department, TA offers are handed down from the top according to some opaque process, and are somewhat of a luxury. The best departments in my field guarantee 1st year TA to all incoming students to let them shop around for advisors.

[the_geneticist]

You might not be the one to make the choice of whether your graduate students get a TA position.  Some programs require the graduate students to be TAs for a certain number of class terms so your "RA PhD students" might still have to teach. 
I don't know your field, but mine still views teaching as a distraction from research and encourages students to minimize their teaching.  Plus, relying heavily on TA funds is seen as "faculty welfare" for folks who can't hack it at grant writing.
So, I'd take on a smaller number of graduate students that you can support from your grants.  Don't assume any money from TA positions.  Also, it seems cruel and biased to have two tiers of grad students.  If someone doesn't look promising, don't offer to add them to your lab.  Hire a technician if you want cheap labor.