10.2 Look-Up vs. Know-From-Memory Decisions

Memory is a navigation tool

For a journeyman exam, memory does not mean reciting the NEC. Memory means you can recognize the topic, choose the correct article path, set up common formulas, and reject answers that are impossible. The open book then supplies exact section language, table values, exceptions, and edition-specific details. This is the balance that keeps a 4-hour exam from becoming a 4-hour index search.

A candidate who memorizes only isolated numbers is fragile. A candidate who remembers only that the answer is somewhere in the book is slow. The stronger approach is layered memory:

This layered model also reduces wrong changes during review. If memory says a question is about branch-circuit required outlets and the book confirms Article 210, you are less likely to be distracted by an answer choice from a service or feeder article.

What to know cold

Some facts should be available without opening the book because they appear constantly or control navigation. Know the ICC exam frame: R17 uses 2023 NEC, T17 uses 2020 NEC, G17 uses 2017 NEC, all are open book, all have 80 questions and 4 hours in the national bulletin, and passing is generally 70 percent for contractor/trades journeyman exams unless the jurisdiction states otherwise. Also remember that ICC provides exam information to licensing agencies; it does not itself grant a state license.

Know the domain map. Wiring Methods, Branch Circuits, Equipment and Devices, Services, and Special Occupancies are high-weight areas. Know the common NEC article addresses: 100 definitions, 110 general requirements, 210 branch circuits, 220 load calculations, 230 services, 240 overcurrent protection, 250 grounding and bonding, 300 wiring methods, 310 conductors, 314 boxes, 430 motors, 500 series special occupancies and equipment, and Chapter 9 tables.

Know formulas and workflows. Examples include watts equals volts times amperes for single-phase loads, volt-amperes as the usual load calculation unit, conductor ampacity before overcurrent device selection, continuous load adjustment where applicable, box-fill conductor equivalents before volume comparison, and raceway-fill area comparison before pullability assumptions. You do not need every table value memorized, but you need to know which table you are trying to reach.

What to look up

Look up exact table values, exceptions, edition-sensitive numbers, and installation permissions that depend on wording. Examples include conductor ampacity table entries, adjustment and correction factors, standard overcurrent device ratings, raceway fill values, box volume allowances, burial cover requirements, motor full-load current tables, support intervals for a specific wiring method, and special occupancy requirements.

Look up when the stem uses limiting words. Minimum, maximum, at least, not permitted, permitted, required, unless, continuous, dwelling, wet location, service conductors, separately derived system, patient care, hazardous classified, and emergency system all suggest the wording matters. A near-memory answer is dangerous when the question asks for a minimum or exception.

Do not look up when the answer is a direct concept you know and the book path would take longer than the value of the question. If a question asks whether loose papers are allowed in the ICC computer-based open-book testing room, the source brief says loose papers are prohibited. If a question asks whether every multiple-choice item should be answered, the no-guessing-penalty rule answers it. Save book time for the NEC.

Lookup route drills

Practice lookup speed with routes, not with broad reading. A route drill has a prompt, a target, and a time limit. For example: Find the box-fill rule for device yokes, Find the table used for raceway conductor area, Find the service disconnect rule family, Find the branch-circuit required receptacle rule, or Find the motor full-load current table used for conductor sizing. Start the timer when you read the prompt and stop it only when your finger is on the rule or table.

Record four times: article reached, section reached, answer confirmed, explanation written. Many candidates can reach Article 314 quickly but lose time inside the article. Others can find Chapter 9 but choose the wrong table note. Measuring the route shows which part is weak.

Index, tabs, and table of contents

The index is useful, but it should not be your only tool. The table of contents is often faster for article families. Tabs are fastest when the article is already known. Informative highlighting can help you find a rule, but excessive highlighting turns the page into noise. Since testing rules can change and depend on administration format, confirm the current ICC bulletin and approved-reference rules before marking or tabbing your book.

Use permanent tabs only where they reduce real time. A tab for every article can become slower than the table of contents. Strong tabs usually include definitions, branch circuits, load calculations, services, overcurrent protection, grounding and bonding, wiring methods, conductors, boxes, motors, special occupancies, and Chapter 9. Add local tabs for your weak domains after diagnostic practice.

Decision rule

Use this rule on exam day: memory for recognition, book for precision. If you recognize the rule, know the answer, and no limiting word changes it, answer from memory. If you recognize the rule but need a number, table row, exception, or exact permission, look it up. If you do not recognize the rule within 20 seconds, mark the question, answer as best you can, and return after easier points are banked.

The best candidates are not the ones who never look up. They are the ones who look up with purpose. Each lookup should either confirm a selected answer, settle a calculation input, or eliminate a tempting distractor. If opening the book does none of those things within a short window, the clock is telling you to move.