Film · 2019 · Films · 2010s
Ma
Scored from 531 calibrated IMDb reviewers, each re-centered on their own rating baseline before the title is ranked. Cohort: Films · 2010s (13,059 peers).
Summary
Sue Ann, a lonely middle-aged woman, befriends a group of teenagers and invites them to party in her basement. The teens quickly discover that her hospitality masks sinister intentions, and what seemed like an escape becomes increasingly dangerous.
Ma is a 2019 horror, thriller and drama film directed by Tate Taylor. Octavia Spencer, Allison Janney and Luke Evans head the billed cast. Its certificate is R. Its country of origin is listed as the United States. It runs 1h 39m.
Rotten Tomatoes carries a separate audience for the same title, 595 of whom clear the calibration test. Its in-cohort standing is measured against the other 13,058 2010s films, not against the whole corpus. The calibrated figure is built from 531 reviewers whose rating history varies enough to place their own average. A broader pool of 546 reviewers with two or more reviews feeds the raw-average track instead.
How the score was built
We compare the reviewers of this title against every other title those same people reviewed. Each review is scored relative to the reviewer's own baseline — a 7/10 from a hard grader sits well above their average, while a 7/10 from a generous grader sits below theirs. Every reviewer then counts the same, so the result is a calibrated consensus rather than a raw average.
- Global percentile
- Where Ma lands against every title we rank.
- In-cohort percentile
- The same comparison narrowed to its cohort — titles of the same format released in the same decade. A 1970s film is judged against 1970s films, not against last year's streaming series. Ranked against Films · 2010s (13,059 titles).
- AI-adjusted percentile
- The same reviewer-normalized score, corrected for how much confidence the sample supports: thin samples are pulled toward the corpus average. Each title keeps the share n / (n + 53) of its measured distance from the average, where n is its calibrated-reviewer count, and the result is ranked on the same scale as the global percentile.53 is the median sample size across everything we rank. Here n is 531.
Cohort: Films · 2010s
