Topic Coherence: The 14% Criterion That Gates Your Entire Score

At 14% of your total AEO Site Rank, Topic Coherence is the single most important criterion in the framework. It weighs more than Original Data (10%), more than Content Depth (7%), more than every technical criterion combined.

Why this much weight? Because AI engines don't just evaluate individual pages. They evaluate domains. When ChatGPT decides whether to cite your site for a question about customer support software, it doesn't just read the one relevant article. It scans your blog, your content inventory, your entire topical footprint. And if that footprint looks like a yard sale - AI tools, smoothie recipes, marathon training, office furniture - the engine concludes you're not an authority on anything.

The scorer works by analyzing up to 50 blog pages from your sitemap. It builds term frequency maps, extracts bigrams (two-word phrases), identifies clusters, and measures how tightly your content orbits around identifiable themes. Brand names and generic web terms get filtered out - only substantive topic words count.

A site like Tidio, where every blog post connects to live chat, customer support, or conversational AI, scores high. A site that blogs about whatever the content team felt like writing that week scores low. The math doesn't care about individual article quality. It measures thematic discipline.

Topic Coherence has a unique mechanic no other criterion shares: the coherence gate. When your coherence score drops below 6 out of 10, a hard cap activates on your entire AEO Site Rank.

The formula: max_score = 35 + (coherence_score * 5)

What that means in practice: - Coherence score 5 = cap at 60. Your site cannot score above 60 no matter what. - Coherence score 3 = cap at 50. Perfect schema, perfect llms.txt, perfect everything - still capped at 50. - Coherence score 1 = cap at 40. You've effectively disqualified yourself. - Coherence score 6+ = no cap. Full score potential unlocked.

This gate exists because topical authority is foundational. A scattered blog undermines every other signal. If AI engines can't figure out what your site is about, they won't cite it for anything - regardless of how technically perfect your markup is.

The gate also affects Content Cannibalization scoring. When coherence is low, the cannibalization checker becomes more aggressive because scattered content is more likely to produce competing pages that confuse AI about which page to cite.

Translation: if your AEO Site Rank seems stuck below 55-60 despite strong technical scores, check your coherence first. It might be the gate holding you down.

The topic coherence algorithm runs four analyses on your blog sample:

1. Term Frequency Analysis Every blog page gets its text extracted (titles, headings, body content). The scorer builds a frequency map of meaningful terms across all pages, filtering out brand names, common web words, and stop words. High-coherence sites show a small number of terms appearing across many pages. Low-coherence sites show a flat distribution where no term dominates.

2. Bigram Clustering Single words are ambiguous. "Support" could mean customer support, structural support, or emotional support. Bigrams - two-word phrases like "customer support," "live chat," "ticket resolution" - are far more diagnostic. The scorer extracts bigrams and checks whether they cluster around identifiable themes.

3. Scatter Detection The scorer measures how many distinct topic clusters it finds. A site with 2-3 clusters scores well. A site with 8+ unrelated clusters triggers scatter detection - the content covers too many unrelated domains to establish authority in any.

4. Cross-Page Theme Overlap For each page, the scorer checks what percentage of its key terms appear on other pages in the sample. High overlap means pages reinforce each other. Low overlap means each page is an island.

The minimum requirement is 3 blog pages with extractable content. Sites with fewer than 3 blog pages get a default mid-range score since there isn't enough data to measure coherence.

Step 1: Audit your existing content List every blog post. Tag each one with its primary topic. If you can't describe your blog's theme in one sentence, you have a coherence problem.

Step 2: Identify and remove off-topic content That company picnic recap, the random holiday greeting, the "10 productivity tips" post that has nothing to do with your business - these are coherence killers. Either noindex them, move them to a separate section (like /company-news/), or delete them.

Step 3: Build intentional topic clusters Pick 2-3 themes directly related to your product or expertise. For each theme, plan a cluster of 5-7 articles that interlink. Example for a customer support platform: - Cluster 1: Live Chat Implementation (pillar + 5 children) - Cluster 2: AI in Customer Support (pillar + 6 children) - Cluster 3: Support Metrics & ROI (pillar + 5 children)

Step 4: Interlink within clusters Every article in a cluster should link to the pillar and to 2-3 sibling articles. This isn't just an internal linking exercise - it reinforces the topical signal the coherence scorer picks up.

Step 5: Establish a content calendar that maintains focus The most common coherence failure is gradual drift. A site starts focused, then someone writes about industry news, then general business advice, then team events. Each post dilutes the signal. Your editorial calendar should enforce topical boundaries.

The fastest path to improvement: audit, remove outliers, cluster what remains. Most sites can jump 3-4 points on coherence in a single focused session of content reorganization.