Illinois students have two major science fair pathways, and knowing which one applies to you is the first step toward competing well.
Students across the state compete through the Illinois Junior Academy of Science (IJAS), while students in Chicago Public Schools compete through the CPS Student STEM Exhibition. Both pathways run from school-level projects through regional and citywide events to state and international competition, and both can carry a strong project all the way to the Regeneron International Science and Engineering Fair (ISEF).
This guide covers how each pathway works, what judges reward, and how to prepare a project that stands out at every level.
The Two Illinois Pathways
Illinois Junior Academy of Science (IJAS)
IJAS supports students in grades 7 through 12 in conducting research and presenting projects at regional and state STEM expositions. Students first compete at one of the IJAS regional science fairs held across the state. Top projects from each region advance to the IJAS State Science Exposition, a two-day event that draws more than 1,200 projects and 2,300 participants from over 600 schools.
The 2027 State Exposition, marking 100 years of student research, will be held April 30 to May 1, 2027 at Bradley University in Peoria. IJAS also operates a pathway that sends its strongest projects to ISEF.
CPS Student STEM Exhibition
Students enrolled in Chicago Public Schools compete through the Chicago Public Schools Student Science Fair, a citywide program run by CPSSSF, Inc. Projects advance from school fairs to regional exhibitions and then to the annual Citywide Exhibition of Student STEM Research, now in its 77th year. The citywide fair is Chicago's route to ISEF, and CPS students have performed at the highest level there: at Regeneron ISEF 2026, Chicago representatives took home Grand Awards including 2nd Place in Chemistry and 3rd Place in both Plant Sciences and Biomedical Engineering.
If you attend a CPS school, the CPS pathway is yours. Everyone else in Illinois competes through IJAS. Either way, the skills that win are the same.
Choose a Research Question Worth Judging
The strongest projects at both fairs start with a question, not a demonstration. Judges can tell the difference between a student who tested something they genuinely wanted to know and a student who rebuilt a project from a list online.
Pick a topic you care about, then narrow it until it is testable with the time, equipment, and safety approvals available to you.
Look for a gap: a local problem (Illinois water quality, urban heat, agricultural runoff), a variation no one has tested, or an accessible version of a method from published research.
Run a thorough background search and literature review before you commit so you can explain how your project differs from what already exists.
Originality within your reach beats ambition you cannot execute. Find out more about what makes a project worth pursuing.
Follow the Rules Early, Not at the Deadline
Both fairs enforce paperwork strictly, and both distinguish between experimental projects and design or engineering projects, each with its own report structure.
For IJAS, the Policy and Procedure Manual on the rules and forms page spells out the required components:
Every project needs an abstract,
A safety sheet,
Any endorsements your topic requires (projects involving humans, vertebrates, or hazardous materials need sign-offs before experimentation begins, not after).
IJAS also publishes how-to videos and hosts office hours with its student board, which are worth attending if anything in the manual is unclear. At the state exposition, papers are collected for a plagiarism check, so cite everything.
For the CPS fair, the calendar of dates and deadlines and category guides on cpsstemfair.org define what your report must include and when it is due. School-level deadlines land months before the citywide event, so build your timeline backward from your school's dates.
The practical rule for both: complete your safety and endorsement paperwork before you collect a single data point. Judges disqualify or downgrade projects with missing signatures no matter how good the science is.
Do Research That Holds Up to Questioning
Judges at the regional, state, and citywide levels are scientists, engineers, and educators, and their questions probe whether you understand your own work. Solid research is your only defense.
Ground your project in a genuine literature review using journals and reputable sources, not just search results. Design your data collection so it can actually answer your question: enough trials, controlled variables, and a method you can defend.
Analyze with statistics appropriate to your data, and know why you chose the test you used. IJAS specifically provides statistics guidance in its how-to resources because judges there expect quantitative analysis, not just charts. Finally, be honest about limitations. A student who can name what their experiment cannot conclude often scores higher than one who overclaims.
Find out more about what judges evaluate in your project.
Present Like You Have Done This Before
At the IJAS State Exposition, poster session students present three times to different judging panels and their scores are averaged, so consistency matters as much as a single great performance. Your board must stay up through all sessions, and you must be present at it. The CPS citywide exhibition similarly puts you in front of multiple professional judges.
Prepare for that format deliberately. Build a poster that communicates your question, method, results, and conclusion to someone walking past in ten seconds, then rehearse a two-minute verbal walkthrough and a longer version for engaged judges.
Anticipate the hard questions: why this method, why this sample size, what would you do next. Practice out loud with someone who will interrupt you, because judges will.
Get Guidance From People Who Have Won With ScienceFair
The single biggest gap between a good project and a winning one is usually feedback: someone who can spot the weak point in your experimental design in September instead of a judge finding it in April.
That is exactly what ScienceFair coaching provides. Our coaches have competed and won at the levels Illinois students are aiming for. Our coaches like these work with students on everything from refining the research question to rehearsing judging interviews, and students in our programs qualify for ISEF at an 89% rate against a national average of 2 to 5%.
If you are preparing for an IJAS regional, the state exposition in Peoria, or the CPS citywide exhibition, book a free consultation to talk through your project and goals with an academic advisor. Winning the fair matters, but the research skills you build along the way matter more.
