• by Laurie Sullivan , Staff Writer, August 12, 2015

Moz released Wednesday its biannual Search Engine Ranking Correlation Study and Expert Survey. The study analyzes keyword use, page load speeds and anchor text  and more than 170 attributes to help identify factors on pages and sites that have the strongest association with ranking high on google.com.

The study doesn't tell marketers whether Google uses the attributes to rank queries, but rather shows the features of pages and sites that are most associated with higher rankings. The analysis digs into the top 50 Google results of 16,521 search queries, resulting in more than 700,000 unique URLs. It only considers English-language, U.S. search results from Google's search engine. The data was gathered during early May 2015.

Links continue to top the list as one of the strongest associations with higher-ranking pages in query results, according to the study. The broad search-ranking factors that are most influential include domain-level links features, based on link citation metrics such as quality of links, trust, and domain level PageRank. Page-level link features rank in at No. 2, such as PageRank, trust metrics, quality of linking root domains, links, anchor text distribution, and quality of linking source. Page-level keywords and content-based features comes in at No. 3. Things related to content relevance scoring, on-page optimization of keyword use, topic-modeling algorithms scores on content, and content quality. (You can read the rest here.)

Some of the more interesting correlation data found in the study involve a lower correlation between keywords on the Web site page and rankings. This suggests the algorithm takes much more into consideration meaning of words, synonyms, close variants, and entities on the page to identify user intent.

Page length, hreflang use, and total number of links all show a moderate association with Google rankings. Using HTTPS also has a very low positive correlation. Negatively associated factors include server response time and the total length of the URL. The data also continues to show some of the highest correlations between Google rankings and the number of links on any Web page.

A section on domain-level keyword use identifies how keywords are used in the root or subdomain name, and how much impact this might have on search engine rankings.

And good news for brands thinking about using top-level domain names other than .com is that the study shows little relationship with the type of top-level domain such as .com, .org, and rankings in Google.