I’m not the best when it comes to stats. But I see some surveys who publish findings based on <30 responses. And I know that these are not valid, and it has something to do with the normal distribution.
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/u/shashwathj, everyone here is answering the wrong thing.
30 respondents is a rule of thumb for when you can use the normal distribution as an approximation for the binomial distribution.
If you have a survey that is asking a yes or no question, that is two options so the distribution for that is the binomial distribution. The binomial distribution is a bit of a pain to work with however but fortunately it starts to look like the normal distribution with more and more respondents. To give non-statisticians a simple threshold for this, we say 30 respondents.
The normal distribution has a simple (by mathematician standards) equation for confidence intervals and so you can quantify the uncertainty in your survey.
There are [other methods for confidence intervals](https://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval) with smaller sample sizes but we can’t teach everyone everything.
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