Google is now better able to reward high-quality Web content that is relevant to a search query, and less dependent on traditional signals, such as keywords, according to a recent report from Searchmetrics.

The report was based on an analysis of the the top 30 search results for 10,000 relevant keywords and 300,000 websites appearing on Google.com in 2015. The aim of the study, which has been carried out every year since 2012, was to identify the key factors that high-ranking Web pages have in common.

Below are four key search engine optimization (SEO) lessons from the report (and therefore likely key elements of an effective SEO strategy). To see the complete list of correlations to search rankings, check out the full analysis.

1. Comprehensive content is more important than ever

Higher-ranking pages tend to have more words and are better able to give searchers the information they are looking for by covering topics more comprehensively, as well as being easier to read and understand, the analysis found.

Since last year. the average word count on pages in the top 10 search results has increased by around a quarter (rising from 975 to 1,285 words, on average).

2. User experience can influence search rankings

Websites that rank higher tend to be better structured and tend to offer a more user-friendly experience.

For example, there is a positive correlation—albeit relatively slight—between search rankings and responsive design. In other words, the better a page ranks, the more likely it is to have employed responsive Web design.