What is an informal outline?

An outline that is written by hand instead of typed on a computer

A comprehensive list of major and minor ideas that a writer plans to include in an essay

A brief list of the major ideas a writer may include in the first draft of an essay

At what point in the writing process is a formal outline typically constructed?

It is most effective to make a formal outline before you do any research.

It is most effective to make a formal outline after you have finished most of your research and formulated a tentative thesis statement.

It is most effective to make a formal outline after you have finished your research but before you have formulated a tentative thesis statement.