What are the most important questions to answer? What are the most important problems to solve? Various people and organizations in the effective altruist community have over the years compiled lists of such questions and problems. This post provides links and brief descriptions of all the lists I’m currently aware of. (Note that many of these lists focus on specific causes, such as artificial intelligence, or on specific disciplines, such as moral philosophy.)

Update: This post was originally written in 2017. Michael Aird has more recently compiled a very comprehensive list of open research questions, which largely supersedes the present list (though Aird’s directory excludes some entries included here).

Further update: 80,000 hours has now released an impressive list of research questions that could have a big social impact, organised by discipline. With the publication of this post, the list below has become obsolete, and is kept here for archival purposes only.

A ranking of the top 10 most pressing global problems, rated by scale, neglectedness, and tractability.

A more extensive list of problem areas outside those listed above.

A list of tractable and important AI-relevant projects. See also their list of possible empirical investigations.

A list of research directions relevant for reducing suffering.

A comprehensive ranking of open research questions, rated by importance.

A survey of research questions for robust and beneficial AI.

A detailed list of important problems.

A list of technical and philosophical questions that could influence OpenPhil’s grantmaking strategy.

A list of valuable research questions, with a focus on the long term. See also Nick’s presentation on ‘Jobs I wish EAs would do‘.

A list of problems in AI Alignment that philosophers could potentially contribute to.

A list of important and neglected problems.

A list of the most important unresolved problems in moral philosophy.

A comprehensive list of potential studies that could, if carried out, illuminate our strategic situation with regard to superintelligence. See also this early post.

A list of questions whose answers would be useful for technical AGI safety research, but which will probably require expertise outside AI to answer.

A short list of the best problems to work on, intended as a supplement to 80,000 Hours’ ranking. See also Anders’ final answer in this interview, which mentions the research questions that he believes are most relevant to space colonization.