# Sample size and data validity.

If you’re conducting tourist behaviour research and wonder how many measurements you need so that you can be confident in the result, this sample size calculator is here to help you. All you need to do is ask yourself these questions before you use it:

• How many travellers visit your region/attraction over a given time period? (Population size))
• What level of confidence do you need? (confidence level)

### How to calculate sample size: an example

We will analyse a sample case step-by-step so you can get a clear picture of how a sample size calculator works.

Let’s assume you are planning to conduct a survey to find out what is the proportion of visitors to your area who visit Location A as part of their itinerary.

• Decide how accurate you want your result to be. Let’s say that it is important for the local tourism body to know the result with a margin of error of 1% maximum.
• From that, we can assume you want to be 99% sure that your resulting recorded dataset is correct.
• Is the total population of travellers so high that you can assume it’s infinite? Probably not. You need to find the current data for the number of travellers to your region – let’s assume it is 25,000.
• All you need to do now is to input all this data into our sample size calculator. It finds the sample size required for the result to have a confidence level of 99% is 648.

So, you need to ask that many travellers to consent to Gulliver services and tracking.

It is worth noting 99% confidence is extreme. 95% certainty of results is more than enough in nearly every case. This would almost half the number of participants required to only 378