Answer:
I would say bias.
Explanation:
bias: prejudice in favour of or against one thing, person, or group compared with another, usually in a way considered to be unfair.
"there was evidence of bias against foreign applicants"
When you are being biased, you are putting your own opinion into what you are doing or you are trying to persuade the person hearing you, reading what you wrote.
Therefore, Evidence without bias increases its reliability.