What is what do you call a sample for which no response is expected?

A sample for which no response is expected is typically referred to as a "non-response sample" or a "mute sample." This could be a group of individuals or participants who have been asked a question or given a task, but do not provide any feedback or respond in any way. Non-response samples can occur for a variety of reasons, such as disinterest, confusion, or inability to communicate.

In research studies or surveys, non-response samples can be problematic as they may skew the results or data collected, leading to biased or incomplete information. Researchers may need to take steps to address non-response issues, such as reaching out or following up with participants, adjusting the sample size, or analyzing the data in a way that accounts for non-response.