11  Who takes classes at Hubbard Hall?

A first look at the class-taking stakeholder group — how many households they are, where they live, how class-taking has changed over time, and how much they overlap with donors and performance audiences. This is a starter chapter; further class questions (which classes, who returns, class-takers as future donors) are queued in the appendix. Distances are straight-line from the hall; see Methodology. How far class and performance audiences travel is compared in How far do people travel to Hubbard Hall?.

import pandas as pd
import plotly.express as px
from hh.io import read_parquet
from hh.viz import style, BLUE, pct

hh = read_parquet("processed", "households_summary.parquet")
regs = read_parquet("processed", "registrations_enriched.parquet")

BAND_ORDER = ["[0, 1)", "[1, 5)", "[5, 10)", "[10, 20)", "[20, ∞)"]

# class-taker geography
ct = hh[hh["is_class_taker"]]
band = ct.groupby("distance_band", observed=True)["id"].count().reindex(BAND_ORDER).fillna(0).astype(int)
within10 = band.loc[["[0, 1)", "[1, 5)", "[5, 10)"]].sum() / band.sum()

# class registrations over time (drop the partial current year)
cls = regs[regs["event_majorcat"] == "class"].copy()
cls["year"] = cls["starts_on"].dt.year
max_year = int(cls["year"].max())
complete_years = sorted(y for y in cls["year"].unique() if y < max_year)
by_year = cls[cls["year"].isin(complete_years)].groupby("year").size().rename("registrations")
ytd = int((cls["year"] == max_year).sum())

# overlap with donors and patrons
n_class = int(hh["is_class_taker"].sum())
n_class_donor = int((hh["is_class_taker"] & hh["is_donor"]).sum())
n_class_patron = int((hh["is_class_taker"] & hh["is_patron"]).sum())
share_class_of_hh = hh["is_class_taker"].mean()

1,853 households — 40% of all households — have registered for a class. Of those, 650 also donate and 758 also attend performances (see How do giving and participation overlap?).

11.1 Where class-takers live

fig = px.bar(band.reset_index().rename(columns={"distance_band": "band", "id": "households"}),
             x="band", y="households", category_orders={"band": BAND_ORDER},
             color_discrete_sequence=[BLUE])
fig.update_layout(xaxis_title="Distance from Hubbard Hall (miles)", yaxis_title="Class-taking households")
fig.update_traces(hovertemplate="%{y:,.0f} households<extra></extra>")
style(fig).show()

Figure 11.1: Class-taking households by distance from Hubbard Hall

61% of class-taking households live within 10 miles of the hall — classes draw mostly from the immediate area, more locally than performances do.

11.2 Class registrations over time

fig = px.bar(by_year.reset_index(), x="year", y="registrations",
             category_orders={"year": complete_years}, color_discrete_sequence=[BLUE])
fig.update_layout(xaxis_title="Year (class start date)", yaxis_title="Class registrations")
fig.update_traces(hovertemplate="%{x}: %{y:,.0f} registrations<extra></extra>")
style(fig).show()

Figure 11.2: Class registrations by year

2026 is year-to-date, so it is left out of the trend. So far in 2026 there have been about 491 class registrations; the full-year total will be higher.