BIOCHEM 990 is a research course for graduate students to conduct independent laboratory work under faculty supervision in preparation for a thesis or dissertation.
Raw average: 4.88/5 from 33 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 4.93/5 from 14 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 4.80/5 from 10 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 4.09/5 from 11 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 4.00/5 from 12 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 4.50/5 from 2 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 5.00/5 from 1 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 5.00/5 from 1 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 3.83/5 from 6 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 3.64/5 from 14 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 3.14/5 from 7 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 3.35/5 from 23 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
Raw average: 3.01/5 from 117 quality ratings. The adjusted rating blends this with the UW review average (3.66/5), weighted as 20 additional ratings. Smaller samples stay closer to that average. Each captured review is counted once in the prior; this does not correct who chooses to leave a review.
RMP profile ↗ · All captured review dates; profile matched by name.
AARON HOSKINS is recorded teaching in Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
ALAN ATTIE is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019. Recorded history may be incomplete and does not establish a future schedule.
ALESSANDRO SENES is recorded teaching in Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
AMY WEEKS is recorded teaching in Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
ANDREW BULLER is recorded teaching in Spring 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Fall 2025. Recorded history may be incomplete and does not establish a future schedule.
BRIAN G FOX is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
BRYCE LAFOYA is recorded teaching in Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
CHAD RIENSTRA is recorded teaching in Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
CHRIS GISRIEL is recorded teaching in Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
CI JI LIM is recorded teaching in Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
DUO XU is recorded teaching in Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
ELIZABETH A. CRAIG is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023. Recorded history may be incomplete and does not establish a future schedule.
ELIZABETH WRIGHT is recorded teaching in Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
HANNAH WAYMENT-STEELE is recorded teaching in Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
HAZEL HOLDEN is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018. Recorded history may be incomplete and does not establish a future schedule.
HECTOR DELUCA is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020. Recorded history may be incomplete and does not establish a future schedule.
IVAN RAYMENT is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Spring 2022. Recorded history may be incomplete and does not establish a future schedule.
JAMES NTAMBI is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Fall 2019, Spring 2020, Fall 2020. Recorded history may be incomplete and does not establish a future schedule.
JASON CANTOR is recorded teaching in Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
JING FAN is recorded teaching in Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
JOHN RALPH is recorded teaching in Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015. Recorded history may be incomplete and does not establish a future schedule.
JUDITH KIMBLE is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023. Recorded history may be incomplete and does not establish a future schedule.
JUDITH SIMCOX is recorded teaching in Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
M RECORD is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025. Recorded history may be incomplete and does not establish a future schedule.
MICHAEL COX is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022. Recorded history may be incomplete and does not establish a future schedule.
MICHAEL R. SUSSMAN is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024. Recorded history may be incomplete and does not establish a future schedule.
MONICA NEUGEBAUER is recorded teaching in Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
OPHELIA VENTURELLI is recorded teaching in Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025. Recorded history may be incomplete and does not establish a future schedule.
PAUL FRIESEN is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
PHILIP ROMERO is recorded teaching in Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025. Recorded history may be incomplete and does not establish a future schedule.
RICHARD AMASINO is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015. Recorded history may be incomplete and does not establish a future schedule.
ROBERT KIRCHDOERFER is recorded teaching in Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
ROBERT LANDICK is recorded teaching in Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
SAMUEL BUTCHER is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
SCOTT COYLE is recorded teaching in Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
SEBASTIAN BEDNAREK is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
SILVIA CAVAGNERO is recorded teaching in Spring 2022, Fall 2022, Spring 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
SNEHAL CHAUDHARI is recorded teaching in Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
SRIVATSAN RAMAN is recorded teaching in Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020, Fall 2021, Spring 2022, Fall 2022, Spring 2023, Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
THOMAS MARTIN is recorded teaching in Fall 2006, Spring 2007, Fall 2007, Spring 2008, Fall 2008, Spring 2009, Fall 2009, Spring 2010, Fall 2010, Spring 2011, Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014, Fall 2014, Spring 2015, Fall 2015, Spring 2016, Fall 2016, Spring 2017, Fall 2017, Spring 2018, Fall 2018, Spring 2019, Fall 2019, Spring 2020, Fall 2020. Recorded history may be incomplete and does not establish a future schedule.
TINA WANG is recorded teaching in Fall 2023, Spring 2024, Fall 2024, Spring 2025, Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
WEI WEI is recorded teaching in Fall 2025, Spring 2026. Recorded history may be incomplete and does not establish a future schedule.
Recorded history may be incomplete and does not establish a future
schedule.
Calendar & sections
Fall 2026
Schedule loads here as you scroll.
Section
Mode
Enrolled / capacity
Waitlist
IND 039
Classroom Instruction
0 / 20
0
IND 040
Classroom Instruction
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0
IND 041
Classroom Instruction
0 / 20
0
IND 043
Classroom Instruction
0 / 20
0
IND 046
Classroom Instruction
0 / 20
0
IND 050
Classroom Instruction
4 / 20
0
IND 053
Classroom Instruction
0 / 20
0
IND 057
Classroom Instruction
2 / 20
0
IND 058
Classroom Instruction
0 / 20
0
IND 059
Classroom Instruction
4 / 20
0
IND 054
Classroom Instruction
0 / 20
0
IND 010
Classroom Instruction
0 / 20
0
IND 066
Classroom Instruction
2 / 20
0
IND 070
Classroom Instruction
0 / 20
0
IND 049
Classroom Instruction
0 / 20
0
IND 071
Classroom Instruction
0 / 20
0
IND 074
Classroom Instruction
4 / 20
0
IND 075
Classroom Instruction
18 / 40
0
IND 076
Classroom Instruction
0 / 20
0
IND 078
Classroom Instruction
6 / 20
0
IND 080
Classroom Instruction
7 / 20
0
IND 081
Classroom Instruction
6 / 20
0
IND 082
Classroom Instruction
0 / 20
0
IND 083
Classroom Instruction
0 / 20
0
IND 065
Classroom Instruction
0 / 10
0
IND 084
Classroom Instruction
0 / 10
0
IND 085
Classroom Instruction
2 / 10
0
IND 086
Classroom Instruction
4 / 10
0
IND 087
Classroom Instruction
3 / 10
0
IND 088
Classroom Instruction
5 / 20
0
IND 089
Classroom Instruction
0 / 20
0
IND 090
Classroom Instruction
2 / 10
0
IND 091
Classroom Instruction
5 / 20
0
IND 092
Classroom Instruction
4 / 20
0
IND 093
Classroom Instruction
2 / 20
0
IND 094
Classroom Instruction
3 / 10
0
IND 095
Classroom Instruction
4 / 10
0
IND 096
Classroom Instruction
3 / 20
0
IND 097
Classroom Instruction
3 / 20
0
IND 098
Classroom Instruction
1 / 10
0
IND 099
Classroom Instruction
2 / 10
0
IND 100
Classroom Instruction
4 / 10
0
IND 101
Classroom Instruction
2 / 10
0
IND 102
Classroom Instruction
1 / 10
0
Times are Central. Select a meeting for details; export includes recorded dates for the selected sections. Enrollment reflects scan time.
Meeting source records
No records available.
Student experience
the class
Independent laboratory research in preparation of a graduate thesis or dissertation under supervision of a faculty member.
difficulty & workload
No workload feedback recorded.
Topics
Laboratory research
Graduate thesis and dissertation
Skills
Independent laboratory research
Thesis or dissertation preparation
Grades
Instructor
Grade distribution · % of letter grades
No grades available yet.
More grade details Grade mix, volume & source data
Sources & history
UW–Madison
Catalog & offerings
Descriptions, prerequisites, and recorded course offerings.
Catalog observation history
Observations at scan time; dates do not imply when a catalog change took effect.