Reading time estimation #172
Description
It would be cool if we could have a configurable setting to display the estimated reading time for a page. Firefox's reader mode does this already, and with some effort I've tracked down the algorithm they use.
The relevant lines are as follows:
_assignReadTime(article) {
let lang = article.language || "en";
const readingSpeed = this._getReadingSpeedForLanguage(lang);
const charactersPerMinuteLow = readingSpeed.cpm - readingSpeed.variance;
const charactersPerMinuteHigh = readingSpeed.cpm + readingSpeed.variance;
const length = article.length;
article.readingTimeMinsSlow = Math.ceil(length / charactersPerMinuteLow);
article.readingTimeMinsFast = Math.ceil(length / charactersPerMinuteHigh);
},
/**
* Returns the reading speed of a selection of languages with likely variance.
*
* Reading speed estimated from a study done on reading speeds in various languages.
* study can be found here: http://iovs.arvojournals.org/article.aspx?articleid=2166061
*
* @return object with characters per minute and variance. Defaults to English
* if no suitable language is found in the collection.
*/
_getReadingSpeedForLanguage(lang) {
const readingSpeed = new Map([
["en", { cpm: 987, variance: 118 }],
["ar", { cpm: 612, variance: 88 }],
["de", { cpm: 920, variance: 86 }],
["es", { cpm: 1025, variance: 127 }],
["fi", { cpm: 1078, variance: 121 }],
["fr", { cpm: 998, variance: 126 }],
["he", { cpm: 833, variance: 130 }],
["it", { cpm: 950, variance: 140 }],
["jw", { cpm: 357, variance: 56 }],
["nl", { cpm: 978, variance: 143 }],
["pl", { cpm: 916, variance: 126 }],
["pt", { cpm: 913, variance: 145 }],
["ru", { cpm: 986, variance: 175 }],
["sk", { cpm: 885, variance: 145 }],
["sv", { cpm: 917, variance: 156 }],
["tr", { cpm: 1054, variance: 156 }],
["zh", { cpm: 255, variance: 29 }],
]);We might want to reverse-engineer Firefox's reader mode to make sure our estimate is hidden though when you enter reader mode too.
Perhaps adding some settings like reading_time_display and reading_time_language would work.
Adding a note to the credits might be a good idea too.