Let's take a look at the information cycle for the September 11th attacks against the US. For a research project, you collect a variety of sources published from the moment the attacks occurred to the present. The first few sources were produced the day of and may contain inaccuracies due to the limited amount of information available at the time. As time progresses, the reliability of the sources increases because facts can be verified and new facts can be discovered.
**Note: the timeline does not contain all of the sources related to 9/11 due to the vast quantity of information available.