The name "Google Dance" has often been used to describe the index update of the Google search engine. Google's index update occurred on average once per month. During an index update there was significant movement in search results and Google showed new backward links for pages. It can be identified by significant movement in search results and especially by Google's cache of all indexed pages reflecting the status of Google's last spidering. But the update does not proceed as a switch from one index to another at one point in time. In fact, it takes several days to complete the index update. During this period, the old and the new index alternate on www.google.com. At an early stage, the results from the new index occur sporadically. But later on, they appear more frequently.
google dance is a inconsistent changes of position in the serp. Sometime you can see your site position in first page sometimes its not listed, then suddenly it goes back just like dancing, changing of movement from time to time...
Google Dance: When google updating Page Rank then we can see fluctuation in Page Rank in toolbar. Where is The Article...