What is the difference between GHHP 99 and GHHP 91?

GHHP 99 is a guided research seminar offered every spring, taught by graduate students, with a regular weekly meeting time. TFs work with students in small groups to complete their research papers. GHHP 91 is similar to an independent study (but graded) where the student is working independently, under the guidance of a faculty advisor, to write his/her research paper. Meeting times are determined jointly by the student and advisor.