Errata: The Busiest Crossing
The idea: a count means little until you know how many had the chance; compare rates, not raw numbers, and go gently with small ones.
Read it
Who is in this book
- Widen One number means little without something to compare it with from NewsForge
- Deed Go to the original document, not a summary of a summary from NewsForge
- Danya a child of the Green Asks "how do we know?"
- Tomas Ask how surprising a result would be, including how surprisingly neat from InferForge
- Attest Every claim names its source, and a correction names one too from NewsForge
- Tara a child of the Green Listens longest, speaks last
Every recurring character has a short tune, so you can tell who is on stage before a word is said. The tunes play only when you tap, and the Reading Access sound switch turns them off.
The Honest Page
Which parts of this story are true, stretched or made up?
True
- A rate compares a count with how many had the chance: accidents per thousand journeys, say, rather than accidents alone. Ignoring how many had the chance, and judging by the count, is sometimes called base rate neglect. Source
- Road safety bodies compare roads by rates, such as casualties per million vehicle-kilometres or per number of people using a crossing, because a busy road will have more incidents than a quiet one even if it is safer for each person. Source
- In the case, six near-misses for three thousand daily crossings is two per thousand; two for two hundred is ten per thousand; ten is five times two.
Stretched
- In the case, the council has a simple count of how many people cross each road every day. What we simplified: Real crossing counts are done on a few sample days and vary with weather, school terms and events, and near-misses are often never reported at all. With counts as small as two and six, a single year can mislead either way.
Made up
- The Green Gazette, its May front page, the petition, the council's count, Ollie, Mrs Fenwick, Mrs Adeyemi and Mr Banerjee are made up. The idea of comparing rates rather than counts is real.
Tara’s sentence
The case stops where Tara speaks. Write the sentence you would have said. It stays on this device.
Kept.
Your sentence lives on this device. Nothing is sent anywhere.
Ring the hammer for someone
Pick this book for someone younger. The link carries only the book, and it will wait for them on the Green.