It's not uncommon for users to make typos while typing. While it might seem like a simple thing, it can be a real problem for search engine designers. Searching through millions of documents might give unexpectedly wrong results if the user typed helo worl instead of hello world. You may be familiar with autosuggestions provided by a search engine. For example, here's how the Google Search interface looks when we type with mistakes:
Pay attention to the two lines at the bottom of the screenshot. One of them says Showing results for hello world, which suggests that the search engine has assumed that the user typed ...
