Voice Search Study: Factors Influencing Search Engine Rankings in 2019

Voice Search in 2019: Our Study

With voice search so hotly discussed and debated this year, we decided to produce a study of our own.

Last year Backlinko produced an in-depth study into the ranking factors behind voice search, with some interesting findings returned. That inspired us to look into this further and understand which ranking factors are continuing to be key, as well as exploring exactly how voice search is continuing to evolve.

Our comprehensive study was lead with two explicit objectives:

1. To understand the parameters that Google Assistant uses to select answers to voice search queries.

2. To compare and understand differences in answers obtained from different devices.

We made it our mission to find out the most essential ranking factors behind voice search as well as uncovering what influences Google Assistant to choose one answer over the rest of the results in SERPs.

Methodology

Our findings are the product of an in-depth analysis of over 50,000 questions asked to three devices combined. Using queries pulled from SEMrush’s API (as well as a series of automated voice queries), we recorded the SERPs from each query and then analyzed several different factors including the readability, page speed, number of backlinks, and SERP features (amongst others) to determine which factors are the most influential when it comes to ranking for voice search queries.

The same process and analysis were then carried out on three separate devices (Google Home, Google Home Mini and the Xiaomi Redmi 6) using Google Assistant; with all three set to the same location to get a conclusive answer.

An In-Depth Review Of Voice Search Findings

One thing we discovered almost immediately was that 97% of answers provided by Google Assistant are results that rank in the top 10 organic results. Therefore an existing first-page ranking is nearly a prerequisite for ranking for voice search queries.

We split our findings into seven key areas:

Average Word Count

Once all the questions were gathered (both manually and by using SEMrush’s API), they were then constructed and curated using three separate methods. Common questions were among those selected, such as “What should I see in Portugal?”, while questions were also created from lists (as well as general questions using popular keywords).

We found that the average word count of an answer from voice search was 41.4, with similar word counts reported across all three devices:

• The Android smartphone had the highest average word count at 43 words. Perhaps the addition of a screen slightly increased this number given that users can read the text while also listening to the audio provided Google Assistant.

• Google Home and Google Home Mini voice search results have an average word count of 41.4 and 42 respectively, suggesting that while the presence of a screen may increase word count marginally, it isn’t a hugely influential factor in producing results across the board.

Rankings

The Android device delivered 93% of answers from the first page of organic results. However, that is still lower than Google Home and its Mini counterpart, both of which delivered 98% of answers from the first page (with over 40% being position one in Google).

Over 60% of results from Google Home were ranking as Featured Snippets in all, a significantly higher number than compared to Android (41%).

In a number of cases, we found answers from the home speaker devices (Google Home and HomeMini) were returning results from the Featured Snippet position. However, when the same queries were conducted using the Android device, the answers produced was not taken from a SERP feature. Example queries included….“Which country is the largest producer of Apple?” and “What Should I See in Portugal”.

Interestingly, while the number of Featured Snippet results within Android are 20% lower than Google Home devices, there was an increase in the number of results occupying a People Also Ask feature.

Around one in five Android voice search queries with SERP features returned answers ranking in a People Also Ask position, while just over one in 10 of searches made via Google Home and Home Mini produce the same result.

There were also many queries where Google Home and Home Mini delivered a Featured Snippet result, but the People Always Ask result was delivered on the Android device; this was the case for results including a number of searches revolving around “which country” questions.

In terms of other SERP features, they were almost non-existent within voice search answers, corroborating the fact that voice search answers come mainly from high-ranking organic results in the Featured Snippet position.

Readability

Sometimes overlooked in SEO is the readability score of the page you are trying to rank. Of course, you can cram a page with target keywords, but what search engines are looking for is well structured, well-written content that ultimately matches the intent of the query.

Within our study, we used a range of different metrics and tools to analyze the readability of results and found that, in general, voice search answers are simple to understand, with the average 15-year-old able to comprehend the answer returned.

Across every metric, the lion’s share of voice search answers performs better than the average of the top 10 non-answers, with Estimate Input Latency particularly noticeable at 70%.

First Paint score also appears as a key metric within voice search, with quicker primary content load speeds more likely to earn voice search recognition as ultimately it will relay the information back to the user more quickly.

Time-to-first-byte also appears to be one of the most critical influences with the speed index metric showing less prominent results, but still providing a strong indication that a faster page is beneficial.

Below is a table representing the queries with the greatest disparity between answers and non-answers.

As you can see from the above data, pagespeed performance is one of the key points to address when optimizing for voice search. In some cases, voice search results were over 10 times faster than the average of non-answers.

From the results, the importance of pagespeed does seem to be slightly more relevant to Google Home and Home Mini in comparison to Android, which is most likely because the latter is still required to load visual page elements alongside voice search results.

Backlinks

Our backlink analysis of voice search answers provides one of the most interesting contrasts across the three devices, with keywords in backlink anchors and page titles much more prevalent in Google Home and Mini results than Android.

Over 50% of answers with Google Home and Mini had backlinks with an anchor that appeared in the question, compared to less than 45% in the remainder of the top 10 results in the SERP. However, with Android, that figure is below the remaining average, signifying a lack of relevance in the case of smartphone devices.

This was also the case with regards to keywords in the query appearing in the title of an answer’s page. A significantly higher percentage of keywords were found in Google Home and Mini answers compared to the rest of the SERP. In the case of Android, the findings were again inconclusive.

Consistent across all devices was the average number of image backlinks. The average number of image links in answers produced by Google Assistant is comparatively low, so there is clearly a connection here to the pagespeed and loading times of a page.

As you might expect from the above, page score and trust score were found to be favored by answers returned from Google Assistant, although answers from all three only offer a slight increase on the rest of the top 10 average of non-answers.

Equally, HTTPS and URL depth also proved inconclusive, largely due to the fact that Google is already encouraging sites to adopt HTTPS and therefore the majority of results within the top 10, and beyond, had already added that extra layer of security.

In fact, of the queries in our study, 90% of results in the top 20 had already converted to HTTPS, proving it a vital factor for ranking well, and hugely relevant if your site has yet to do so.

In Conclusion