Search Engine Algorithms: What You Need to Know

Search engine algorithms are formulas and rules that search engines use to decide which web pages to show when someone enters a query. They analyze factors like relevance, quality, and user experience to organize the search results and help people find the best answers.

In a way, the search engine algorithm is like rocket science: we know it’s important, but most of us aren’t exactly sure how it works.

Every year, Google rolls out numerous updates (often with little to no warning) that manage to change the playing field for marketers in big and small ways.

But even for pros who have been working in search engine optimization (SEO) and paid search for years, understanding the search engine algorithm can be tricky. Knowing the basics allows you to react to new changes quickly or prepare your campaign for them in advance.

What are search engine algorithms?

Search engine algorithms are a collection of formulas that determine the quality and relevance of a particular ad or web page to the user’s query.

From Bing to Yahoo, every search engine has its own algorithms (or “rules”) and Google reportedly changes its algorithm hundreds of times each year.

The good news: only major changes (or updates) have the power to affect SEM campaigns significantly.

How do search engine algorithms work?

Each search engine algorithm is made up of sub-algorithms that perform different tasks. At the most basic level, search engine algorithms have three jobs: to crawl, index, and rank web pages.

1. Crawl: Bots (aka web crawlers) scan web pages and follow links.
2. Search index: The crawled content is stored in a large database organized by topics (keywords).
3. Rank: When someone enters a search query, the search algorithm analyzes the indexed content in its database to find the most relevant, high-quality, and authoritative pieces and display them on the results page in order of importance.

Overall, the Google search engine uses more than 200 ranking factors when determining which results to serve and in what order.

However, no matter how well you adjust to them, each new update has the power to push your efforts to square one.

While updates may be mostly focused on organic search, they can have not-so-clear (but oh-so-painful) implications for paid search as well.

For example, your ads could stop showing up as a response to a big part of your target audience’s queries simply because the landing page they lead to isn’t specific enough.

What is the purpose of search algorithms?

Search engine algorithms were created to:

1. Help search engines understand the user’s intent
2. Identify the most relevant, helpful, high-quality content
3. Present that information in an organized manner

What factors influence search rankings

While we might not know the exact set of rules for each search engine’s ranking algorithms, we do know key factors that influence which content is chosen to appear on the SERP.

These factors include:

• • Keywords: How well the website content matches the search query
  • Content quality: Original, accurate, well-written, valuable, and relevant information
  • Backlinks: The quantity and quality of external sites linking to the page
  • User experience (UX): How fast the page loads, mobile-friendliness, usability, and intuitive navigation
  • Domain authority: The credibility and trustworthiness of the website, along with the age of the domain
  • Freshness: How recently the content was published or, better yet, updated
  • Engagement: Click-through rates, dwell time, and bounce rates
  • Structured data: Use of schema markup to help search engines understand content

• On-page SEO: Title tags, meta descriptions, headings, URL structure, and alt text

Pro tip: While social media isn’t a direct ranking factor, it can indirectly impact SEO (and rankings) by increasing website traffic.

Types of search engine algorithm updates

Not all updates are created equal.

It’s nearly impossible to monitor all the updates Google comes up with and still have time to focus on your marketing strategy.

• Major updates: These updates are infrequent and often address a specific search algorithm issue. For example, the Core Web Vitals update addresses problems related to user experience on web pages. Search engines usually release them once or twice a year.
• Broad-core updates: Updates in this category focus on targeting low-quality pages. Usually, they adjust the importance of several ranking factors. For example, they may decide that page loading speed is now more important than the total number of backlinks. These updates usually occur once every 4-5 months.
• Small updates: These updates don’t usually create major visible changes to your site’s performance and analytics. They’re often minor tweaks that improve the searcher’s experience and don’t affect the rankings of high-quality websites. Minor updates can be implemented daily or weekly.

Basically, major and broad-core updates are worth your attention. However, only a few of them are strong enough to make a significant impact on your rankings.

Google algorithm examples

With each new Google update, search engine algorithms are working to become more useful to the searcher. Unfortunately for digital marketers, predicting specific changes is nearly impossible.

By understanding the overall intent to improve the searcher’s experience, it’s possible to adjust your SEM strategy so it doesn’t suffer as new updates take effect.

1998: PageRank

In 1996, Larry Page and Sergey Brin (co-founders of Google) created the PageRank algorithm at Stanford University as an effort to better organize searched content.

Essentially, the PageRank algorithm determined which sites were more important than others — and if important sites linked to other sites, those associated sites were more likely to be considered important as well.

This early algorithm was all about trustworthiness and credibility.

2011: Panda

The Google Panda algorithm update was designed to reward high-quality content while penalizing lower-quality, thin, and spammy content.

This update went after sites that stuffed keywords in their content, and those with high bounce rates and low user engagement were negatively impacted.

2012: Penguin

The 2012 Penguin update cracked down on spammy backlinks, targeting websites that used black hat tactics like link schemes.

This update rewarded those with natural, high-quality links and was integrated into Google’s core algorithm in 2016.

2013: Hummingbird

Google Hummingbird focused on better understanding search intent. In other words, it shifted from relying only on keywords to interpreting the meaning and context behind user queries.

This algorithm update helped Google improve the relevance of results for more complex, conversational, and long-tail searches.

2015: RankBrain

The RankBrain update also helped Google further understand user intent and context behind search queries.

But while Hummingbird was focused on semantic search, RankBrain leveraged machine learning to interpret user intent and handle more ambiguous or complex queries.

2019: BERT

This update’s aim was to improve the search engine’s translation of natural language queries to improve its understanding of context.

This forced marketers to pay more attention to user intent than before. Pre-BERT, if you needed to focus on separate keywords in the search phrase, full phrases became much more important after the update.

For example, the query “cooking your own vegetables” shouldn’t simply give a list of tips for cooking veggies. It should also provide tips for cooking vegetables you grew and harvested on your own. In turn, paid ads had to become much more specific targeting the intent of the audience to stay relevant to search queries (in addition to leveraging personal data, user behavior, and search history).

2021: MUM

In May 2021, Google announced its Multitask Unified Model update, or MUM. This AI is designed to analyze content similar to the way a human does. Google calls MUM a powerful evolution of the BERT algorithm.

MUM’s goal is to process complex search queries that can’t be satisfied with a short snippet. To get answers to these query types, a user needs to do an average of eight searches.

To address this problem, MUM works to predict these searches and provide answers on the first search engine results page (SERP).

When adjusting your SEM strategy for MUM, it’s wise to focus on:

• A high-quality internal linking system
• Leveraging structured data
• Working to predict complex queries as part of the buyer’s journey so you can provide answers
• Creating multi-tiered content and splitting it into snippet-friendly fragments

2022: Helpful Content Update

Focused on user-first content, the Helpful Content Update targeted websites that produce low-quality content designed to rank on the SERP rather than provide value for the searcher.

Content that is helpful and created by subject matter experts is now prioritized over sites with unoriginal or thin content.

Pro tip: If you’re focused on user experience (as you should be), then these updates shouldn’t have a major negative impact. However, if you do see your rankings take a dive, here’s how to deal.

How to optimize for search engine algorithms

Search engine updates can be as unpredictable as the weather. The only thing you can know for sure is that they will happen.

When they do, many websites and ads may see a drop in rankings, even if the change is temporary. Luckily, there are ways to stay prepared and ready when updates do arise.

1. Continue ongoing SEO maintenance

The most important step to prevent the negative effects of algorithm updates is to continue routine SEO maintenance in conjunction with creating high-quality content.

From technical SEO basics (improving site speed, mobile friendliness, and indexing) and on-page SEO staples (proper use of keywords and metadata), to a quality backing strategy and user experience, make sure to audit your site regularly and keep an eye on important metrics for optimization opportunities.

2. Focus on landing page quality

Even when updates roll around, it’s hard to understand immediately how they’ll affect the connection between paid and organic search.

But one thing is always clear: High-quality content on landing pages is likely to affect your conversion rate positively, regardless of algorithm changes.

Just a few years ago, landing pages weren’t as important for paid search because they didn’t play a big role in the ad-clicking process.

Today, with Google’s focus aimed at search relevancy and accuracy, landing page quality is an integral factor, particularly when determining things like your Quality Score.

Search engines pay close attention to the landing page quality and relevance to keywords, and that isn’t likely to change.

Now, Google even tracks how often a user returns to the search page after visiting the landing page in an attempt to understand whether they were satisfied with the search result.

To stay ahead of the updates, it’s imperative to maintain the quality and relevance of both landing and linked pages.

3. Don’t rely solely on keywords: focus on intent and relevance

Google algorithm updates tend to move away from a hyper-focus on keywords to more long-tail phrases and nuance.

Of course, keywords are still an integral part of SEM. However, building your strategy solely around them can prevent you from seeing the big picture or creating a well-rounded program.

Rather than only focusing on your keyword, you also want to take intent and relevance into account. Look into how you can best answer the questions your audience is asking.

Paying attention to when, how, and what they ask can help you design relevant content while satisfying changing search engine algorithms.

It can help to focus on the buyer’s journey instead of only on single keywords that users type when starting the search.

For example, Google has a different view of relevance with the roll-out of MUM. Now, it evaluates how your content or landing page fits into the context of the subject.

This includes relevant backlinks, internal linking for content clusters, and proper Schema markup.

4. Look for update warnings

In some cases, search engines will offer some advanced notice about an upcoming algorithm update.

Back in April 2020, Google announced a 2021 algorithm change that would introduce Core Web Vitals as ranking factors.

This gave marketers more than a year to get familiar with these new factors and adjust accordingly. Since Google isn’t always forthcoming about algorithm update details, it’s wise to take notice when they are.

5. Don’t panic — but do update your content

When search engines change their algorithms, it can cause chaos for marketers. It’s often a mad dash to adjust strategies and make quick changes to curb significant ranking changes or irregular reports. But sometimes these actions can hurt your campaign even further.

Remember, all you can do is implement relevant improvements and follow the latest guidelines.

If you’re using Google Analytics, making note of when an algorithm update took place can explain any out-of-the-ordinary results when you pull reports or debrief clients.

Algorithm update or not, it’s always best practice to revisit your content regularly to ensure it offers value and aligns with the search intent to be considered the most relevant result.

Pro tip: If another company’s site starts outranking you after an algorithm update, you can run a competitor analysis to figure out why that might be.

The takeaway

Search engine algorithms are a complex system for helping users find the best answer to their queries. And to improve user experience, search engines change their algorithms regularly.

But studying how algorithms work isn’t as important as understanding what your target audience wants.

By improving the quality and relevance of your page content while exploring questions your audience asks, you can work to minimize your dependence on algorithm changes and control, to some degree, how drastically they affect your initiatives.

Need some help along the way? We’ve got you.

This article has been updated and was originally published in November 2020.