Hillcrest · San Diego · Since 2019
Good tutoring is quiet, patient and very specific.
Marrowstone is a small, independent tutoring studio for grades 6–12. We work one-on-one or in groups of three, in person on Ocello Street or online, and we send parents a short written note after every session.
- 0tutors on staff
- 0min. or 90 min. sessions
- 0students max per group
What we do
Help for the subject in front of you — and the habits behind it.
Most students who come to us aren't failing. They're stuck on one unit, overwhelmed by a schedule, or preparing for something that matters to them. We start with the actual homework and tests, figure out where things break down, and build from there.
Every student has a single lead tutor, so nobody has to explain themselves twice. When a second subject is needed, the tutors talk to each other.
Read about the studio →
Subjects
What students work on with us
Math
Pre-algebra through AP Calculus AB/BC and Statistics.
02Writing
Essays, research papers and college personal statements.
03Sciences
Biology, Chemistry and Physics, including AP and honors.
04Test prep
SAT, ACT and AP exam strategy with timed practice.
05Study skills
Planners, note-taking and executive-function coaching.
06Languages
Spanish I–IV and AP Spanish Language.
How it works
Four steps, no long contracts
- 1
Consultation
A free 30-minute call or visit with Kenneth or a lead tutor.
- 2
Diagnostic session
One working session to see how your student approaches problems.
- 3
A written plan
Goals, session frequency and a check-in date, sent by email.
- 4
Notes after each session
What we covered, what's next, and anything you should know.

From the studio
“We'd rather spend twenty minutes on why a student got one question wrong than rush through twenty questions they half understand.”
— Kenneth Porter, founder
Our approachWho we help
A good fit if your student…
is in grades 6–12 at a public, private or charter school
needs steady weekly support rather than a crash course
is preparing for SAT, ACT or AP exams in the next year
has an IEP or 504 plan and needs extra structure
is homeschooled and wants an outside instructor for one subject
is applying to college and wants honest feedback on essays
Questions
A few things parents ask first
Do you require a long-term commitment?
No. Sessions are billed monthly and you can pause or stop with 7 days' notice.
Can sessions be online?
Yes. About half of our sessions run online with a shared whiteboard. The tutor and plan stay the same.
Do you guarantee grade or score improvements?
We don't. No honest tutor can. We do promise consistent, prepared sessions and clear communication.
Not sure where to start?
A 30-minute consultation is free. We'll talk about your student, look at a recent assignment, and suggest a plan — no obligation.