Semi-finalist:

In the 2005-2006 competition, 1684 students entered the competition. After the deadline for paper submissions, which is usually in early October, the papers are blind read by a judging panel. At this stage of the competition, the judges know nothing about the students who have written the papers. I think that the abstract is weighted pretty heavily in this judging phase due to the number of papers the panel has to read under the time restriction they are given (only 20 days for 1684 papers!). Around mid-October, the Siemens Foundation posts the list of the 300 semi-finalists whose papers will be further judged for Regional Finalist selections. The list of semi-finalists is also published in USA Today the following week. All semi-finalists receive a backpack full of prizes, including a digital camera in the past.

Regional Finalist:

Judging for the Regional Finalist round is a second round of readings by the panel. Now that there are only 300 papers to read, I assume that judging is a lot more in-depth at this phase. Papers are judged on creativity, quality of experimental work, knowledge in field of research, depth of details, clarity, validity, use of literature, scientific importance, and future work. In late October, thirty teams and thirty individuals are selected to move onto the regional finalist round. Regional finalists receive all-expenses-paid trips to the regional finalist round. Regional finalist judging takes place at six universities around the United States. Students are usually assigned to compete at the university closest to them.

National Finalist:

Judging for the National Finalist round comprises of a poster presentation, a twelve-minute oral presentation, and an interview.