How LexiMap Works

LexiMap is built on a simple insight: the English language is not random. Thousands of the words that appear on the SSAT and ISEE trace back to a relatively small set of Latin and Greek roots. By teaching those roots systematically — and reinforcing them with spaced repetition and varied practice — students gain the ability to decode unfamiliar words on test day, even words they have never studied directly.

The Root Word Approach

Most vocabulary programs hand students a long list of words to memorize. LexiMap takes a different approach. Instead of memorizing definitions one word at a time, students learn 166 Latin and Greek roots — the building blocks that recur across thousands of English words. Based on our content mapping analysis, these 166 roots cover approximately 76% of the vocabulary tested on the SSAT and ISEE.

Consider the Latin root bene, meaning "good" or "well." A student who internalizes this single root can unlock the meaning of benefactor (one who does good), beneficial (producing good results), benediction (a good saying or blessing), benevolent (wishing good), and dozens of other words — without having to study each one individually.

This strategy is grounded in morphological awareness, the ability to recognize and manipulate the meaningful parts (morphemes) of words. Research in reading science has consistently shown that morphological awareness is a strong predictor of vocabulary size and reading comprehension, particularly for academic and low-frequency words — exactly the kind that appear on standardized tests.

Rather than learning 2,000 isolated definitions, a student who masters 166 roots develops a transferable skill: the ability to break down any unfamiliar word into recognizable parts, infer its meaning, and confirm that inference from context. This is far more durable and flexible than rote memorization. For a complete reference of the roots we teach, see our complete list of Latin and Greek roots for SSAT vocabulary.

FSRS Spaced Repetition

Knowing a root once is not the same as knowing it permanently. Without reinforcement, newly learned information fades — a phenomenon documented by over a century of research on the spacing effect and forgetting curves. LexiMap addresses this with the FSRS (Free Spaced Repetition Scheduler)algorithm, one of the most advanced open-source scheduling algorithms available.

FSRS tracks each student's memory state for every root word individually. After each practice interaction, the algorithm updates its estimate of how well the student knows that root and calculates the optimal time for the next review. Roots the student finds easy are scheduled further out; roots that are still shaky come back sooner.

LexiMap targets a 89.6% long-term retention rate using FSRS, significantly outperforming massed practice (cramming) which research consistently shows produces weaker long-term recall. The result is that students spend their study time where it matters most — on the roots they are closest to forgetting — rather than re-reviewing material they already know well.

For families preparing for the SSAT or ISEE, this means that vocabulary learned in August is still accessible in November, and a student who practices 10 to 15 minutes per day builds a steady, cumulative foundation rather than a fragile one that evaporates after a cramming session. For a detailed breakdown of how to structure daily practice and set realistic improvement timelines, read our parent's guide to improving SSAT verbal scores.

The 5-Skill Mastery Model

Recognizing a root in a multiple-choice list is not the same as using it to decode a novel word in context. LexiMap measures mastery across five distinct skills, ensuring that students develop deep, flexible knowledge rather than shallow recognition:

• Recognition — Identify the correct meaning of a root when presented with options. This is the foundational skill: can the student recall what bene means?
• Construction — Build words from component parts. Given the root bene and a set of prefixes or suffixes, can the student assemble a real English word?
• Derivation — Work backward from a complete word to identify its root and infer meaning. Given malevolent, can the student identify mal (bad) and vol (wish)?
• Context — Determine the meaning of a word using root knowledge plus sentence context, mirroring how vocabulary is actually tested on the SSAT and ISEE.
• Analogy — Recognize relationships between words that share roots or have complementary meanings, directly practicing the analogy question format used on the SSAT.

Every root in LexiMap is practiced through all five skills. A root is not considered mastered until the student demonstrates proficiency across every skill type, ensuring genuine depth of knowledge.

Content Architecture

LexiMap's 166 roots are organized into 17 chapters across 6 difficulty levels. The curriculum is calibrated for every SSAT and ISEE test level:

• Level 1-2 — Elementary Level SSAT (grades 3-4) and Lower Level ISEE (grades 5-6 entry). High-frequency roots with concrete, familiar derived words.
• Level 3-4 — Middle Level SSAT (grades 5-7) and Middle Level ISEE (grades 7-8 entry). Intermediate roots with more abstract derived words and multi-root combinations.
• Level 5-6 — Upper Level SSAT (grades 8-11) and Upper Level ISEE (grades 9-12 entry). Advanced roots, low-frequency vocabulary, and complex morphological patterns.

Chapters are designed to be completed in sequence within a level, with each chapter building on vocabulary and skills from the previous one. The spaced repetition system works across chapters, so roots from earlier chapters continue to appear in review sessions as the student progresses.

When a student selects their test level during onboarding, LexiMap automatically calibrates which chapters and difficulty settings are active. Students preparing for a higher-level test can always access lower-level content to fill foundational gaps, and the diagnostic assessment helps identify where to start.

9 Interactive Game Modes

Vocabulary practice should not feel like a chore. LexiMap uses 9 distinct game modes to keep sessions engaging and to exercise different cognitive pathways:

• Drag & Drop Matching — Drag roots to their correct meanings or derived words.
• Tap Select — Quickly tap the correct answer from a set of options.
• Swipe Sort — Swipe words left or right to categorize them by root family.
• Word Builder — Assemble words by combining roots, prefixes, and suffixes.
• Context Clues — Read a sentence and select the word that fits based on root meaning.
• Analogy Chains — Complete word-pair analogies, directly mirroring the SSAT format.
• Root Radar — Identify the hidden root inside a set of related words.
• Speed Round — Timed rapid-fire recognition to build automaticity.
• Story Fill — Complete a short passage by choosing root-derived words that fit the context.

Sessions are organized as quests — short, focused practice runs of 8 to 12 questions that typically take 3 to 5 minutes. The quest structure makes it easy for students to fit practice into a busy schedule and provides natural stopping points. Each quest mixes game modes and skill types based on the student's current learning needs, as determined by the FSRS scheduler.

Research Foundations

LexiMap's design draws on several well-established lines of research in cognitive science and education:

Morphological Awareness

Studies have consistently demonstrated that explicit instruction in morphological analysis — teaching students to identify roots, prefixes, and suffixes — leads to significant gains in vocabulary knowledge and reading comprehension. This effect is particularly strong for academic vocabulary, the register most heavily tested on the SSAT and ISEE. Research by Bowers, Kirby, and Deacon (2010) found that morphological instruction produced reliable improvements across grade levels and student populations.

The Spacing Effect

The spacing effect — the finding that distributed practice produces stronger long-term retention than massed practice — is one of the most robust findings in learning science, replicated across over a century of research. Cepeda et al. (2006) conducted a comprehensive meta-analysis confirming that spaced practice consistently outperforms cramming for long-term retention of factual material. The FSRS algorithm implements this principle by calculating optimal review intervals for each individual item.

Retrieval Practice

Each of LexiMap's game modes requires active recall — the student must retrieve information from memory rather than passively re-read it. Research on the testing effect (Roediger & Butler, 2011) has shown that actively retrieving information strengthens memory traces far more effectively than re-studying. By varying the retrieval format across 9 game modes and 5 skill types, LexiMap ensures that knowledge is encoded through multiple pathways, making it more accessible under the time pressure of a real test.

Interleaving and Varied Practice

Rather than drilling one root exhaustively before moving to the next, LexiMap interleaves practice across multiple roots and skill types within each quest. Research on interleaving (Rohrer & Taylor, 2007) suggests that mixing related but distinct items during practice improves the ability to discriminate between concepts and strengthens long-term retention, even though it may feel more challenging in the moment.

SSAT® is a registered trademark of The Enrollment Management Association. ISEE® is a registered trademark of ERB. LexiMap is not affiliated with or endorsed by these organizations.