11.9% of ISEF finalist names from 2014 to 2026 (2,308 people) appear in more than one year. Their later projects (2,368) won grand awards at 37.8%; projects by one-time finalists (12,189) won at 22.4%. Projects that describe themselves as a continuation (Year 3, Phase II) are 3.1% of entries (252) and win at 31.7% against 26.9% for the rest. Korea has had 13 returning finalists in 13 years.
Why the second trip does better
The data do not state the cause, but the explanation is plain. A returning student has sat through the judging interview and the poster session, has pushed the same question a year deeper, and already knows the affiliated-fair selection process. Continuation projects cluster in Translational Medical Science (24), Animal Sciences (21), Earth and Environmental Sciences (20), Environmental Engineering (17), Biomedical and Health Sciences (16) and Plant Sciences (14), where a dataset or an organism can be carried forward.
Repeat detection matches full names within a fair country, so people who share a name may be counted together. For countries with many common names, including Korea, treat the count as an upper bound.
Applied to a two-year plan
2028 dates are not published yet, so only the month is shown. Grand rates are 2014 to 2026 base rates and promise nothing.
- A grade 9 or 10 first entry is the set-up. It is a 22% shot in its own right, but the goal is the judging experience and the depth of the question.
- The grade 11 or 12 return is the realistic award shot. Carrying the same question into a Year 2 means the data, the baseline and the limitations are already in hand.
- Count backwards. ISEF is in May and Korean selections are decided in December and January, so year-one results must exist by the preceding November. KSEF 2027 national-division registration runs 2026-11-23 to 12-22.
- Declare continuation work honestly. The 2026 to 2027 ISEF rules require a continuation form (Form 7) and disclosure of prior work when a project builds on earlier research. The procedure is covered in the KSEF and ISEF AI research guide.
Frequently asked questions
Data and method
Two public sources. From the Society for Science abstract database (abstracts.societyforscience.org) we compiled every ISEF finalist project from 2014 to 2026: 17,565 projects with title, category, fair country, awards and full abstract. From the isef.net project library we took the award-tier flags for the 8,134 ISEF projects of 2021 to 2026 and joined them to the abstracts by year and booth id. Compiled on 2026-10-11.
A grand award means a First to Fourth Award or Best of Category, roughly the top 27% of each category. A special award is given by a sponsoring organization with its own judges. ISEF 2020 was held without judging and is excluded from every rate. The abstract database carries no 2025 awards and misses most Materials Science grand awards after 2017, so award flags for 2021 to 2026 combine both sources. An AI mention means the title or abstract contains a machine-learning term; it does not mean the project is about AI. All numbers are correlations, and Korean per-category figures rest on 2 to 24 projects, so read them as direction rather than precision.
Sources
- https://abstracts.societyforscience.org/
- https://isef.net/search-results/projects
- https://www.societyforscience.org/isef/international-rules/
The figures on this page are category-level base rates compiled from public ISEF results. They do not predict or promise any student's award, selection or admission. CIT does not guarantee awards, selection or admission.
ISEF data series
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