(noun) an idea of how something is, or how it should be done
concept
(noun) a single person
individual
(noun) a typical or common amount of something
average
(noun) ways of communicating information or news to people
media
(noun) the usual way of doing something
norm
(noun) someone who finds out information
researcher
(phrase) to trust in
rely on
(noun) someone who offers to do something for free
volunteer
(noun) a scientific test
experiment
(verb) to experience something
encounter