How does the act of observation influence what is observed?

We are all constantly engaged with the action of observing. We observe the environment around us for every daily activity we do (walking, talking, listening, etc.). The act of observing itself is one of the most powerful powers that a creature could have, because it allows the living-being a better sense of what is going on in its environment. But the act of observing is influenced and thus manipulated due to many automatic generalizations human’s have.  For instance using the context of our surrounding environment is something that we do all the time (which is a very helpful skill at many incidents). But using the context around us and filling in the blanks for what we do not see is not always a good indictor of what is actually happening. Human error also plays a huge factor in our observations reality. The errors that we are known faulty of are all widely accepted (through uncertainty, etc.) and could be a huge factor in the difference from what we observe to what there is in reality. Memory is also an unhelpful tool when trying to remember what we have previously observed, since we estimate many things based on their context or what we find normal. When trying to remember a certain incident, people often use the context and generalize the aspects of what they had observed to fil in the blanks for the details they could not remember. The experience a person has with a certain event also plays a huge factor in how the person observes it or later rememorizes the event. In general we can always be skeptical for what we observe due to the role of context, estimation, human error, memory, experience, and etc.