In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

Question: What are, among others, the main biases associated with the observer in the framework of observation techniques ?:
Options: <0> The duration of the experiment. <1> The excess of information. <2> The technical accuracy <3> The illusion of learning. <4> The expectation and mechanical errors of registration.
psychology