Sources and corrections
Educational material is more useful when readers can tell which claims are well supported and when a page has limits.
Source preference
For factual topics, Study Commons prefers primary or high-authority sources such as museums, universities, government agencies, scientific organizations and original research where appropriate for the learner level.
Attribution
When a reading depends on specific external facts, sources are listed on the page. The wording, examples and practice questions are written for Study Commons rather than copied from those sources.
Corrections
When a material error is found, the goal is to correct the page rather than preserve the mistake for appearance's sake. Major corrections should also update the page's modified date where relevant.
Uncertainty
Some questions in science and history do not have one final answer. In those cases the page should separate observation, interpretation and reasonable inference instead of presenting speculation as fact.