Type I error in A/B tests

In A/B tests, there are multiple considerations that come into play when obtaining a sample that accurately represents the population.

If the population is not accurately represented with the data used in the analysis, a Type I error can be found, providing an incorrect result or conclusion. Factors influencing the likelihood of a Type I error should be monitored to be aware of, and reduce, the Type I error rate.

Which of the following considerations is likely to increase the likelihood of obtaining a Type I error?