The terms we use, in plain English.

Review trajectory

How an apartment's rating has moved over time, rather than a single all-time average. The trajectory shows whether a place is trending up or down — the thing an average hides.

Change-point

The specific month an apartment's rating meaningfully shifted (for example, held at 4.2★ then fell to 2.7★ over a couple of months). We detect it with statistical change-point analysis, not by eyeballing.

Per-capita crime rate

Police-reported offenses normalized by population — offenses per 1,000 residents per year — so cities of different sizes can be compared fairly. We show it against the state and national average.

NIBRS reporting gap

Years a police agency didn't report to the FBI (notably the 2020–21 transition to the National Incident-Based Reporting System). We show these as gaps in the line, never as zero.

Walkability index

The EPA National Walkability Index, a 0–20 score for a census block group based on street connectivity, transit access, and the mix of nearby destinations.

AQI

The US Air Quality Index. We show a recent average and the worst-day peak near an address; in valleys, winter inversions drive the peaks.

Owner-response rate

The share of reviews a property's management replied to — and how often they engage with the negative ones. One of the strongest signals in a review set.

Review-gating / astroturf

When a property steers happy renters to leave reviews and discourages unhappy ones, or posts bursts of fake 5-stars. We flag unusual spikes as worth a closer look — we never accuse a person.

Corroboration

When the same complaint shows up across independent review sources. Independent agreement is a strong trust signal; a 5-star burst that appears on only one source is a caution.

See it applied on any building report, or read the methodology.