You have probably noticed that, particularly when checking up on the positions of a site you are familiar with, when you search Google, Yahoo or Bing the description that is shown isn’t always what you’ve set as the meta description tag. The title you are shown is usually what you’ve set within the title tag and the URL stays the same but the description, or snippet isn’t quite what you expected. Snippets usually do relate to your search query but when your description tag isn’t good enough, how are alternatives generated and where is the information pulled from?

The snippet performs a couple of functions – it gives you a summary of what the page is about, and it shows you the context within which your query terms might appear on a page. Sometimes the search engine will decide to display the meta description tag if it feels it is most relevant to the search query you have entered. Other times it displays different information from various different places.

Sometimes it will display a snippet of text from your page’s content if it feels something you have written is more related to the search query. But sometimes it will display text not even found on your website. In this case, where is the information coming from?

If the search engine decides that the page is relevant to your search query but the content doesn’t give a good enough summary in relation to the search query it can pull information from various other places that has a better description, including the Yahoo Directory or DMOZ.

If snippets aren’t very informative, in relation to the search query, it may deter people from clicking onto particular websites or they may not click onto the most helpful or relevant websites. Poor quality snippets can lead to a poor searching experience so the search engines are fine-tuned to deliver quality and relevant information for as many websites and searchers as possible.