A bias or point of view is someone's personal opinion on a subject, If we were talking about a sports team and someone is very led towards a particular team you could say he has a bias towards that team. Many scholars or professors can be bias or have a bias towards something.
The way a bias can change the way events are interpreted can be the fact that not everything is said or not everything is said in complete detail.
You could also point out the fact that a detail is completely ignored in an event because of someone's bias.
