# \[Troubleshooting] The report indicated a statistical reliability yesterday, but today it doesn’t The most likely cause of this error is that your sample size is too small. Only predefined sample sizes that are large enough create significant differences and meaningful results. If your sample (the number of visitors tested) is too small, the test loses its value. \ We recommend you calculate the sample size you need to attain using a [***sample size calculator***](https://www.abtasty.com/sample-size-calculator/) before running a statistical test. It is also recommended to wait a few extra days before consulting your results, even if your sample size is large enough, so you can account for user behavior on different days of the week. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.abtasty.com/help-center/troubleshooting/troubleshooting-the-report-indicated-a-statistical-reliability-yesterday-but-today-it-doesnt.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.