At first glance, reviewing just 200 calls might seem too small—especially when your contact center handles thousands (or millions) of them every month.
But we chose this number for a reason. A randomly selected sample of 200 calls is a fast, statistically sound way to uncover what truly matters in your conversations—without spending hours combing through endless recordings. Here’s why that small number packs a big punch.
To see Balto in action, check out Balto Insights.
“We Handle Thousands of calls a month. How can 200 be enough?”
Totally fair question.
It feels like the more calls you have, the more you need to review. If you have 150 agents each taking 500 calls a month, sampling just 200 calls sounds tiny.
But here’s the twist:
It doesn’t matter how many total calls you have.
What matters is how the sample is picked.
Let’s walk through an example.
Say your contact center handles 75,000 calls per month, but you sample 200 calls and find that 15% mention something weird—like people asking about stinky cheese. That’s 30 out of 200 calls.
You might think, “But we had 75,000 calls total—maybe that 15% number is way off!”
Statistically? It’s not.
Even with just 200 randomly selected calls, we can be 90% confident that the real number is somewhere between 11% and 20%. Sure, that’s a lot of cheesy chatter—but statistically speaking, it’s still a representative sample of all your calls. It’s actionable data that doesn’t string you along.
If you sampled 500 calls instead, that range tightens a bit—12.5% to 17.8%.
With 1,000 calls, it gets even tighter—13.2% to 16.9%.
But here’s the key:
The story doesn’t change.
Only the decimals do.
So…why not sample more?
You can. But it takes more time and a lot more money (more calls = more processing).
And you usually won’t learn anything new.
For most use cases—like spotting new issues or trends—sampling 200 calls is:
✅ Fast
✅ Accurate
✅ Enough to act on
In Summary:
The accuracy of your sample doesn’t depend on how many total calls you have. It depends on how many you look at.
200 calls is enough to spot real trends.
Going bigger barely changes the results.
It’s the smartest balance of speed, cost, and accuracy.
If you have further questions, feel free to schedule a conversation through our demo page or contact your Balto Account Executive or Customer Success Manager.
Additional Resources:
“Binomial Proportion Confidence Interval.” Wikipedia, Wikimedia Foundation, https://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval. Accessed 12 Apr. 2025.
“Confidence Interval.” Wikipedia, Wikimedia Foundation, https://en.wikipedia.org/wiki/Confidence_interval. Accessed 12 Apr. 2025.
