If time permits, let these discussions continue until students finish, rather than providing a pre-set time limit. Scientists believe that things and events are understandable through careful study. Scientists follow rules of argument to advance their ideas. A scientific theory is a single framework of ideas that logically relates many observations. A good imagination is necessary for a scientist to think of ways to test a theory with observations or experiments.
Science has rules for evaluating evidence.
Scientific theories are continuously tested with new evidence. A scientific experiment is a formal procedure to explore an idea. Lance finds the story hard to believe and is trying to evaluate the evidence. Whether the account he is hearing is first or second-hand is one criteria for evaluation, as stories often become distorted as they pass from one person to the next. The account by Reverend Harvey of receiving a piece of giant squid tentacle from a fisherman was from a first-hand witness and was accompanied by physical evidence.