That is correct because in order for your question to be testable it has to be able to be repeated by another person. For example, a question like "what type of music gets people in the mood to study / work?" is a testable question because multiple people would be able to test it and get valid results. But a biased question like "what is your favorite breed of dog?" is not testable becuase it is opinion based and somebody can repeat it, yes, but scientific questions aren't based on opinions. I hope this helped!! :)
