Most families treat "the science fair" as one event. It is a ladder with four or five rungs, each judged differently, each cutting a different share of projects, and each rewarding a slightly different thing. Students who understand the ladder prepare for the rung they are actually on. Students who do not bring a school-fair project to a regional and wonder why it stalled.
This is the full path, from the school gym to Regeneron ISEF, and what decides advancement at each step.
The ladder at a glance
| Level | Who judges | Typical field | What advances | What is scored |
|---|---|---|---|---|
| School fair | Teachers, parents, a few local professionals | 30 to 200 projects | Top few per grade or category to regional | Effort, completeness, basic method |
| Regional / county fair (ISEF-affiliated) | Volunteer scientists, engineers, teachers | 100 to 600 projects | Category winners to state; 1 to 3 Grand Award projects direct to ISEF | Creativity, method, data, interview |
| State fair | Same pool, more PhDs and industry judges | 200 to 1,000 projects | Category winners; in some states, additional ISEF slots | Same rubric, higher bar on originality |
| Regeneron ISEF | Category-assigned judges, mostly PhDs | ~1,700 finalists from 60+ countries | Grand Awards, special awards, ~$9 million total | 100-point rubric: 25 points interview |
Numbers vary by region. The pattern does not: the field shrinks by roughly 10x at each step, and the share of the score that comes from the interview grows.
Round 1: the school fair
What it is. Many schools require a project in a science class; others run an optional fair. Judges are typically teachers and parent volunteers, with a few local engineers or doctors if the school recruited them.
How judging works. Usually one rubric, one or two judges per project, 5 to 10 minutes each. Scores emphasise completeness: did the student follow the scientific method, is there a hypothesis, a procedure, data, and a conclusion.
What advances. The top few projects per grade or per category are nominated to the ISEF-affiliated regional fair. Some schools skip this round and let students register for the regional directly; check with your science department.
What wins here. A clean, complete project with a clear question and a board that reads well from six feet away. Depth matters less than it will later. Do not over-engineer this round; just do not get cut on a formatting detail.
The trap. Students who win the school fair with a demonstration project ("which paper towel absorbs most") advance to a regional where every competitor ran an actual experiment with real variables. Pick a project that can survive two more rounds, not just this one.
Round 2: the regional or county fair
This is the first serious round, and for most students the most important one, because it is the gate to both state and ISEF.
What it is. Regional fairs are affiliated with Society for Science, which means they follow ISEF rules: the ISEF forms, the Scientific Review Committee checks, the category system. Find yours through the Society for Science fair finder.
Who judges. Volunteers recruited from local universities, hospitals, and companies: working scientists, engineers, graduate students, retired professionals, and teachers. They are assigned to broad categories, not subfields. Your judge is almost never an expert in your specific topic, and that fact should shape your entire pitch.
How judging works. Three to six judges visit each project independently, 10 to 15 minutes each. Each scores against a rubric modelled on ISEF's: research question, design and methodology, execution and data, creativity, and presentation. Scores are averaged; judges then caucus by category to rank the top projects and resolve disagreements.
What advances.
- Category awards (first, second, third in Biology, Engineering, and so on). Category winners typically advance to the state fair.
- Grand Awards. The top one to three projects across all categories, selected in a second-round judging pass, go directly to ISEF as the regional's finalists. This is how most ISEF finalists qualify.
- Special awards from sponsors (a university, a professional society, the military). These do not advance you but matter for your resume.
Where projects get cut. Three places: the Scientific Review Committee (paperwork missing or human/animal approvals not done before experimenting), the first judging pass (judges did not understand the project), and the Grand Award caucus (project understood but not original enough).
What wins here. A project with a real variable, real data, correct analysis, and a student who can explain it to a non-expert in 60 seconds. At the regional level, communication is the tiebreaker more often than science. Two solid projects, one clearly explained, and the clear one takes the category.
Round 3: the state fair
What it is. Most states run a state science and engineering fair that draws category winners from every regional. In some states the state fair is itself ISEF-affiliated and sends its own finalists; in others ISEF slots are allocated only at the regional level and the state fair is a separate honour with its own scholarships.
Who judges. The same pool as regionals, but larger fairs attract more PhD researchers and industry specialists, so the chance of meeting an expert in your area rises. Prepare both the plain-language pitch and the technical defense.
How judging works. Same structure: multiple independent interviews, rubric scores, category caucus. The bar moves on originality and scope. A regional-winning project that replicates a known result will place mid-pack at state; the winners asked a question nobody had asked, or asked a known question with a method nobody had used.
What advances. Category and grand awards, state scholarships, and in ISEF-affiliated states, additional ISEF finalist slots. Senior-division winners often also qualify for invitations to national competitions.
What wins here. Novelty you can state in one sentence, plus a result with real error bars. Judges at state ask "what is new here?" in the first two minutes. Have the answer ready.
Round 4: Regeneron ISEF
What it is. The largest pre-college science competition in the world: around 1,700 finalists from more than 60 countries, roughly $9 million in awards, held each May. You reach it only by winning an affiliated fair's ISEF slot; there is no direct application.
Who judges. Judges are assigned by category and are mostly PhDs or equivalent, recruited nationally. You are still unlikely to get a subfield specialist, but the technical floor is much higher than at a regional.
How judging works. Each finalist is interviewed at least four times, 15 minutes each, by different judges across the judging day. The published rubric is 100 points: research question 10, design and methodology 15, execution 20, creativity 20, presentation 35, of which the interview is 25 and the poster 10. Read the full ISEF rubric breakdown and how to win the ISEF interview.
What is awarded. Grand Awards in each category (first through fourth), the top-of-show awards ($75,000 and $50,000), and hundreds of special awards from sponsors. Roughly a quarter of finalists leave with a Grand Award.
What wins here. Original work with a result that holds up under four rounds of expert questions, presented by a student who clearly did it. Independence is scored explicitly. Mentored projects are normal, but the student must own every decision in the interview.
What changes as you climb
Three things shift from the school gym to ISEF, and preparing for them early is the whole game:
Where YRI fellows have gone
Avyay Gupta won first place at his regional fair in ninth grade with a project built on public genetic and pollution data and qualified for state. Mubashir Suhail qualified as a Regeneron ISEF 2026 finalist through his national affiliated fair. Both projects were planned from the start to survive the full ladder, not just the first rung.
Free download: The Science Fair Project Kit
Seven printable worksheets that take a project from first idea to judge-ready: hypothesis builder, experiment design, data log, board layout, and the ISEF scoring rubric with interview prep.
Frequently Asked Questions
How many projects advance from a regional science fair to ISEF? Typically one to three per affiliated fair, chosen in a Grand Award round after category judging. Larger regionals get more slots.
Do I need to win my category to go to state? Usually category first-place, and sometimes second, advance. Rules vary by state; check your regional fair's advancement policy.
Can I enter a regional fair without a school fair? Often yes. Many ISEF-affiliated regionals accept direct registration through a teacher sponsor. Ask your science department or the fair's website.
How many judges will I see at a regional? Three to six, each for 10 to 15 minutes, scoring independently before a category caucus.
Is the same project allowed at the fair and at JSHS? Yes. JSHS is a separate competition with a paper and oral presentation instead of a board. See JSHS round by round.
Related guides
- Your science fair judge is not an expert in your field
- How ISEF is judged: the 100-point rubric
- ISEF 2026 guide: how to qualify
- ISEF forms and teacher sponsor guide
- Science fair deadlines 2026-27
- How to win a science fair