There is no doubt that this year’s Panda and Penguin updates have caused significant changes. We found that the best strategy is to understand Google’s goals and how they might implement them in their algorithm.
One major goal is to increase the relevancy of the search results. Incorporating backlinks in their algorithm was their major breakthrough to increase the quality of their search results.
Many of the updates have to do with getting better at downgrading links that are for manipulating the search engine results. However there are also updates that related to the quality of the content on the site. For example, duplicate content is a problem.
Google probably also looks at metrics that signal content quality. Lowering the bounce rate will help in this case.