The hardest design problem in any directory is the same problem every time: who do you put at the top? Get it right and your readers come back. Get it wrong and you become Yellow Pages — full of every business in town, useful to none.
Kisimenti uses one number to decide. We call it credibility. It's not a star rating, it's not a popularity contest, and it's not for sale. This piece explains exactly how it works.
The formula
Every business in our directory gets a credibility score. The formula is:
A worked example: a restaurant with 4.7 stars across 1,200 reviews, with phone + website + hours + photos + recent reviews all on file:
- Rating component: 4.7 × log₁₀(1201) = 4.7 × 3.08 = 14.48
- Signal component: 5 signals × 0.5 = 2.50
- Total credibility: 16.98
Now contrast: a brand-new café with 5 stars across 3 reviews, no website or hours on file:
- Rating: 5 × log₁₀(4) = 5 × 0.60 = 3.01
- Signals: 1 × 0.5 = 0.50
- Total credibility: 3.51
The 4.7-star institution ranks far above the 5-star stub — which is what most users want. Broad sustained enthusiasm beats unproven perfection.
Why a logarithm?
Linear weighting on review count is unfair to the long tail. A business with 10,000 reviews isn't ten times more credible than a business with 1,000 — it's just been around longer or is bigger. The logarithm captures the diminishing returns of additional reviews: going from 0 reviews to 10 matters enormously; going from 1,000 to 10,000 less so. The 1,000th review is the difference between one customer and clearly proven; the 10,000th is the difference between clearly proven and clearly proven plus one.
This means we can compare businesses with very different scales fairly. A high-rated boutique with 200 reviews can rank above a mediocre chain with 5,000.
What the signals reward
The five quality signals each add half a point. They're independent observable markers that a business is active and real:
- Phone number on file — they want to be reachable.
- Website on file — they care about their digital presence.
- Opening hours filled in — they expect customers to come.
- Photos on the profile — there's a visible business there, not just a registry entry.
- Recent reviews (≥5 in the last 6 months) — the business is still operating.
A fully-signal business gets +2.5 to its score. A signal-empty business gets nothing. This corrects for the fact that some businesses have great ratings but are essentially digital ghost listings.
What we don't include
Equally important is what's not in the formula:
- Whether the business pays for a Kisimenti subscription. No effect on rank. Paying for Pro or Premium unlocks features (verified badge, custom domain, ad placement) — never ranking position.
- Whether the business has claimed their profile. An unclaimed listing can outrank a claimed one if its credibility score is higher.
- Editorial preference. No human override. The formula is the formula.
- Negative-event signals like fines, scandals. We don't have the data sources for these in Rwanda yet, and we wouldn't want a single negative news event to wipe a business out unfairly.
What the formula doesn't capture
Three things we know we're missing, that you might:
- Recency of reviews. A business with 1,200 reviews from 2018-2021 and zero since gets the same score as one with 1,200 fresh reviews. We'll add a recency decay in v2.
- Review quality. A 50-word review counts the same as a 2-word "good" review. The 50-word one is obviously a stronger signal.
- Local vs out-of-town reviewer signal. A 5-star from a tourist who visited once isn't the same as a 5-star from a regular. We don't currently have a way to distinguish.
Why we'd rather be transparent
Most directories don't publish their ranking formulas — because if you publish them, you make it easier to game them. Our reasoning is the opposite. A formula that can be gamed by a few people writing five-star reviews is a formula that's been gamed for years already. Publishing it lets the businesses we rank see why they're where they are, and gives serious operators a clear set of things to improve. The directory gets better.
If we ever need to change the formula — recency weighting, review quality, anti-spam adjustments — we'll publish the change here and explain why.
More on how Kisimenti works: What is Kisimenti — and why every business in Rwanda needs to be on it. Questions or methodology feedback? Contact us.