What are investigatable and non-investigatable questions?

Investigatable questions are those that can be answered through observation, experimentation, or research, allowing for empirical evidence to support conclusions. For example, "What factors affect plant growth?" can be tested through controlled experiments. In contrast, non-investigatable questions are often subjective or philosophical, lacking a clear method for empirical investigation, such as "What is the meaning of life?" These questions typically elicit personal interpretations rather than definitive answers.