The Unkindness of Ravens were inspired by figures from Norse and Celtic mythology such as the Valkyries and The Morrígan. Filming took place during 2014 in Fife, Edinburgh, and Perthshire, and moved into post-production in 2015. To help with costs, Brewster opened a crowdfunding campaign through Kickstarter, with the goal to raise £40,000. The campaign was successful and marked the first Scottish crowdfunding campaign to raise such a large amount of money and the highest funded British horror film on Kickstarter. Horror film critic Kim Newman reviewed "The Unkindness of Ravens", writing that it was "a demanding, complicated film which might well require repeat
Collectively exhaustive events or not. For example, tossing a particular biscuit for a group of several dogs cannot be repeated, no matter which dog snaps it up. One example of an event that is both collectively exhaustive and mutually exclusive is tossing a coin. The outcome must be either heads or tails, or p (heads or tails) = 1, so the outcomes are collectively exhaustive. When heads occurs, tails can't occur, or p (heads and tails) = 0, so the outcomes are also mutually exclusive. The term "exhaustive" has been used in the literature since at least 1914. Here are a few examples: