What is jury nullification? Under what circumstances might this be more likely to occur in a trial?

What will be an ideal response?

Sometimes juries disagree with the law, thus raising the controversial issue of jury
nullification. Because juries deliberate in private, they can choose to disregard, or
"nullify," the judge's instructions. The pages of history are filled with poignant
examples. Consider the case of someone tried for euthanasia, or "mercy killing.". By
law, it is murder. But to the defendant, it might be a noble act on behalf of a loved one.
Faced with this kind of conflict— an explosive moral issue on which public opinion is
sharply divided— juries often evaluate the issue in human terms, use personal notions
of commonsense justice, and vote despite the law for acquittal (Finkel, 1995?
Niedermeier et al., 1999). This
nullification tendency is particularly likely to occur when jurors who disagree with the
law are told of their right to nullify it (Meissner et al., 2003). In these instances,
research suggests the possibility that a nullification instruction may unleash a form of
"chaos," liberating jurors to follow their emotions in an emotionally charged case
(Horowitz et al., 2006).