The study looked at different ways indoor lighting is set up and how it affects energy use and brightness. They tested 14 lighting setups and found that having more equal lighting across a room saves energy. A setup with just one light used the most energy, while one with more lights was the most energy-efficient. When light is spread out evenly, the room seems brighter with less energy needed. Having lights placed symmetrically also makes a room seem brighter with lower energy use. They also created a simple way to predict how much energy lighting setups save. This suggests that having just one light in a room might be wasting energy, and adding more lights can help save energy while keeping things bright.