Most families applying to Silicon Valley private schools will encounter one of two standardized admissions tests: the ISEE (Independent School Entrance Exam) or the SSAT (Secondary School Admission Test). The two tests assess similar content — verbal ability, reading comprehension, and mathematics — but they differ in format, scoring, and which schools require them.
In Silicon Valley, the ISEE is more commonly required. The Harker School requires ISEE scores for most grade-level applications. BASIS Independent Silicon Valley uses its own internal entrance assessment. Cambrian Academy and Fusion Academy Cupertino do not require standardized admissions testing — their admissions process is based on application, interview, and in some cases a shadow day visit.
ISEE vs SSAT — side-by-side comparison
| Category | ISEE | SSAT |
|---|---|---|
| Administrator | ERB (Educational Records Bureau) | SSATB (Seton Hall) |
| Levels | Primary (Gr 2–4), Lower (Gr 5–6), Middle (Gr 7–8), Upper (Gr 9–11) | Elementary (Gr 3–4), Middle (Gr 5–7), Upper (Gr 8–11) |
| Sections | Verbal Reasoning, Quantitative Reasoning, Reading, Math Achievement, Essay | Verbal (Analogies + Synonyms), Quantitative (2 sections), Reading, Essay |
| Wrong answer penalty | No penalty — blank = wrong = same result | Yes — 1/4 point deducted per wrong answer |
| Score scale | Stanine 1–9 per section + percentile | Scaled score + percentile |
| Frequency | Once per testing season per level | Multiple attempts allowed per season |
| Used by Harker School | ✓ Required | Check with school |
| Used by BASIS Ind. SV | Own assessment used | Own assessment used |
| Used by Cambrian Academy | Not required | Not required |
| Used by Fusion Academy | Not required | Not required |
Which test should your student take?
Start by confirming which test each of your target schools requires. Do not assume — check each school's current admissions page for the active application cycle. Testing requirements can change year to year.
If your primary target is The Harker School, plan for the ISEE. The Harker School uses ISEE scores as part of its holistic review process. Strong ISEE scores do not guarantee admission — Harker receives significantly more applications than it accepts — but weak scores will limit your application.
If you are applying to multiple schools with different requirements, the ISEE is typically the safer primary investment because it is more widely required among Silicon Valley independent schools. Students can take the ISEE once per testing season at each level, so prep timing matters significantly.
Prep timeline for Silicon Valley families
Most Silicon Valley families begin ISEE or SSAT preparation 4 to 6 months before their target application deadlines. For schools with December 2026 deadlines, that means starting prep by June or July 2026. For schools with January or February 2027 deadlines, starting September 2026 is the minimum timeline for adequate preparation.
AJ Tutoring in Los Altos (4.9 stars, 134 Google reviews) specializes in ISEE and SSAT preparation for Silicon Valley private school applicants. They have former school admissions staff on their team and offer both in-person tutoring and online sessions. Most competitive Silicon Valley families working with a tutor begin 4 to 6 months before their test date, with weekly 60 to 90-minute sessions.
Schools that don't require standardized testing
Not all Silicon Valley private schools require ISEE or SSAT scores. Cambrian Academy (84 students, grades 6–12) does not require standardized admissions testing — their process focuses on application, student and parent interviews, and a campus visit or shadow day. This makes Cambrian accessible to strong students who are not high-stakes test takers.
Fusion Academy Cupertino also does not require ISEE or SSAT scores. Given their 1-to-1 model, Fusion's admissions process focuses on understanding each student's individual learning profile, goals, and schedule needs rather than standardized test performance.
For families considering schools across the testing spectrum, our full admissions timeline guide covers every step from open houses through enrollment deposits.