objectively
In a way based on facts, not feelings or opinions.
Objectively means based on facts rather than feelings or opinions. When you look at something objectively, you're trying to see it as it really is, not as you wish it were or as it seems through your personal preferences.
If you're deciding objectively which backpack to buy, you might measure how much each one holds, check how sturdy the zippers are, and compare the prices. These are facts anyone can verify. But if you choose based on which color you like best or which one your friends have, you're not being objective anymore. You're letting your feelings and preferences guide you.
Scientists work hard to observe things objectively, measuring and recording what actually happens rather than what they hoped would happen. A judge tries to look at evidence objectively, focusing on facts rather than personal feelings about the people involved. When your teacher grades objectively, she marks answers as correct or incorrect based on whether they match the facts, not on whether she likes particular students.
The opposite of objectively is subjectively, which means based on personal feelings, tastes, or opinions. You can objectively measure that one student ran the mile in six minutes and another in seven minutes. But is the sunset beautiful, or which flavor of ice cream tastes best? Those are subjective questions where personal feelings matter more than measurable facts.