Observational instruments are tools used to gather data by observing phenomena in various fields, such as astronomy, meteorology, and biology. Common examples include telescopes for viewing distant celestial objects, microscopes for examining tiny organisms, and cameras for capturing images of events or environments. These instruments help scientists and researchers collect accurate information, enabling them to analyze and understand complex systems. By using observational instruments, they can make informed decisions, develop theories, and contribute to advancements in knowledge across multiple disciplines.