Agnotology is the opposite of epistemology - it is the study of ignorance. This includes both misinformation, the spread of wrong info, and disinformation, the intentional spread of wrong info. It does not cover the metaphysically unknowable realm, but rather the historical and political reasons for information being kept private, uncertain, or unknown.
Robert Proctor distinguishes between three views of ignorance:
Ignorance as native state: This is an intuitive understanding of ignorance and it is often adopted by scientists. On this view, ignorance is a hole waiting to be filled with knowledge. People originate in ignorance and replace it with knowledge as they learn.
Ignorance as lost realm: This perspective understands ignorance as occupying a space. Nobody can be knowledgeable of everything. When we learn one thing, we are giving up the opportunity to learn something else.
Ignorance as social construct: Ideas are spread throughout society by idea-communicators. These ideas can either be right or wrong and, if wrong, their communicators can either be aware or unaware of this wrongness. Ignorance is something humans construct and spread.
Some of the key examples of disinformation in recent times are: global warming denial, intelligent design, and the major tobacco companies' denial of smoking-induced health risks. The tobacco industry has been perhaps the most transparently duplicitous. Brown & Williamson Tobacco Company's internal memo in 1969 was: "Doubt is our product." Proctor describes the process by which these corporations fund researchers to produce non-incriminating results so that they can (1) generate public uncertainty over the health side effects of smoking cigarettes, and (2) show their research in court to prove that they are honestly investigating the effects of their products.
Understanding the strategies used to keep people ignorant can be helpful for (1) preventing these strategies and (2) generating strategies for spreading good memes and true information.