A Complete Introduction To Nabla Site Structure

Most common technical SEO issues

In this article I will be introducing you to a site structure that I coined the term for as nabla structure. It's easily one of the best structures to use on the web, so I highly recommend giving it a full read.

Did you know there is a word for a reverse pyramid?

It’s an ancient greek word, loosely meaning inverse triangle. It’s also named after the instrument the harp.

And it’s called Nabla.

It also just so happens that it’s latent structure makes for one of the best ways to organize information, including your websites overall architecture (and even articles in cases).

So to be true to its origins, let’s be fair and call it Nabla Structure.

Ready to dive in?

A 2-Minute Intro To Information Architecture For SEO

Before we go any further, let’s just clarify some terms.

Search Engine = Information Retrieval & Indexing.


Information Architecture = Core part of SEO.

Ok, next...

What Are Taxonomies?

A taxonomy is described as something that classifies things or concepts.

There are many types of taxonomies, one such taxonomy is hierarchical taxonomy.

Hierarchical taxonomic structures follow a parent/child structure.

Hierarchical Structures

Almost all successful websites consciously or unconsciously follow a hierarchical structure that works something like:

Category > Sub-Category.

Often described as the Parent/Child Relationship.

A taxonomical hierarchy

Hierarchy intrinsically make sense to human beings, and because of this we’ve developed sites, crawlers and much more accordingly.

Attempts to create other such taxonomies on the web have been unsurprisingly unsuccessful.

The Most Famous Hierarchy In SEO

The most famous hierarchical structure in the SEO industry is called the Silo Structure.

Unfortunately this is where most SEOs knowledge of information architecture ends.

An attack on the silo structure often sounds the same as an attack on hierarchy.

But it’s not.

The reality is that silo structure is a great hierarchy...

But it’s not always the best, and quite often it doesn’t work for a lot of site types and sizes.

And in my opinion it doesn’t work as well as it used to generally.


Silo structure always worked because it helped search engines create relevance associations.

Dozens of core updates, and hundreds if not thousands of minor algorithm changes later…

Google doesn’t need strict site structure to help define relevance anymore.

The reason all of this is relevant, is because a silo visually is a triangle.

The opposite of what Nabla is.

Both are hierarchies, but fundamentally different.

The shift in the search landscape and the improved ability to understand relevance through our content has made one of these hierarchies better than the other for search.

Before we go on, let me just recap quickly...

If you’re still with me at this point then you probably agree;

  • Site Structure Matters
  • Hierarchy Is The Best Taxonomy (For Most Sites)
  • There are many ways to achieve a Hierarchical Structure

Nabla Structure ∇

So we’ve covered some of the fundamentals, and we’ve addressed the elephant in the room.

Now onto the good stuff.

Information Hierarchies are studied in colleges and universities around the world by students of all kinds.

Bottom line up front
Source - TheConfidentTeacher

In colleges, journalists are taught to structure their information in an order that places the most important or relevant information in the most accessible place.

When it comes to this hierarchy of information, they found that the “inverted pyramid” (Nabla) is what invariably works best.

  • At the macro level - your site architecture.
  • At the micro level - your articles, etc.

On the web, for well over a decade we SEOs have been doing almost the exact opposite of what journalists found worked.

While it worked for rankings for a time, it’s arguable that it ever truly worked for content.

Attention-spans are depleting, user engagement metrics importance is growing. Might be time to try something new?

And when it comes to search, it feels like crawl issues become ever more important, most of which come back to the way your site is setup and is actively harmed by the silo approach to hierarchy.

nabla structure vs silo structure

What it is that we’re seeing is that across the board, with both content and site structure is that providing the most relevant information in the most accessible place is working better.

So how do you do it?

Nabla Structure Fundamentals:

Broad and shallow is best.

Based on the structure it’s better to build a “shallow” structure rather than a “deep” one.

To achieve this more categories, with less sub-categories always works better than a few categories with many sub-categories.

Bottom-line: Start growing sites laterally rather than longitudinally.

File pages/posts under the category that is most specific.

It’s important to first create the correct categories, and then file content in the correct ones… Use clear categorization to make this easy for yourself, but also most semantically relevant.

Always make sure that you create concise and unique categories that don’t conflict. Create a new category rather than file it in the wrong one.

Note: You can file in multiple categories, but I prefer to avoid this as standard practice. It’s also important to get your primary category correct if you do this.

Bottom Line Up Front

Also known as BLUF or TL;DR. This style of communication emphasizes placing the most important information in the most accessible place.

In the case of your overall site structure, this means your navigation… The growing trend of sites utilizing extensive dropdowns in their menus is no coincidence!

How To Setup Nabla On Your Website

The main thing to know about Nabla is that there is really only one rule...

That rule is that you try to make your information as easily accessible as possible.


This is one of the reasons it works so well for sites right now, because if you’re following that rule, most URLs are only 1 or 2 clicks from the homepage. (In some bigger sites 3 is also acceptable).

Most good auditing tools check this for you, such as SiteBulb.

SiteBulb Crawl Depth

They call this crawl depth, but you can use this interchangeably with the terms click depth and levels.

  • CD 0 - Homepage
  • CD 1 - Directly accessible from the homepage anywhere on the site.
  • CD 2 - Directly accessible from a CD1 page.

It’s pretty simple, but a lot of people get this mixed up, so it’s important to know these few facts about crawl depth so that you can actually optimize for it correctly.

People often assume that you can make a page Crawl Depth 1 by adding a link to it from the homepage.

That’s wrong.

You actually need to make it accessible from every page on your site, by 1 click.

This is why the main menu and footer menu matter so much, as well as sub-menus.


This is an area where most sites we work with have slipped up if they’ve already implemented a friendlier structure to begin with.

If your categories or “parent pages” contains 100 articles, you will most likely see 10x10 pages or 5x20 pages. (Note: The same applies to products.)

Each page makes your site deeper, and so that’s no good.

You have two options -

A.) Increase the # of “child nodes” displayed on the page.

B.) Create more categories and restructure the existing articles/products into more relevant sections.


The categorization part is often overlooked as well, because most people think of this as merely a crawl depth issue. But it’s not, that’s just a happy byproduct!

Categorization is what makes hierarchies work.

So like any hierarchy, it’s not going to work well at all if you fail at the first hurdle.

Today there are many methods you can use to help categorize your content correctly, but the easiest one is always going to be using your own knowledge and supplementing it with searching online.

If you want to get really scientific, I recommend checking out Google’s Natural Language API Demo

Why Nabla Works

There are many reasons this works...

It works because it provides a much better user-experience...

It works because it makes crawling your site much easier.

And one of the main reasons in my opinion that it works so well is because it’s so simple and complex at the same time…

It's dynamic so you can adapt it to fit your needs as your websites requirements change over time.

Other types of hierarchies, such as the silo have stricter rules that don’t work as well as your site scales and grows.

For example, a silo structure requires silo style internal linking at all times... With Nabla, so long as you follow the broad-shallow architecture you can get a lot more creative with internal linking.

You can use the same rules you use in a silo, but only for contextual links (non-navigation). You can utilize a network taxonomy linking style like Wikipedia.

A network taxonomic structure

It gives you a lot more freedom and control with your site, as all it’s really doing is setting out the foundational structure of your site.

For this reason alone I can’t recommend it enough for those serious about optimization like myself.

The bottom-line is that nabla structure is just the best thing since sliced bread.

P.S. If you think this article will help you, do me one solid? Just give it a share on your favorite social network or group. It’s good to share 👌

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