Google has announced that they made 52 changes in April. Which of these changes are relevant to your website rankings and how do you have to react to these changes?
The following changes have the biggest impact on the position of your web pages on Google's search result pages:
Improvements to how search terms are scored in ranking. One of the most fundamental signals used in search is whether and how your search terms appear on the pages you’re searching. This change improves the way those terms are scored.
Keyword stuffing classifier improvement. We have classifiers designed to detect when a website is keyword stuffing. This change made the keyword stuffing classifier better.
More authoritative results. We’ve tweaked a signal we use to surface more authoritative content.
More domain diversity. Sometimes search returns too many results from the same domain. This change helps surface content from a more diverse set of domains.
These first two items probably refer to the Penguin and Panda updates that Google released last month.