Taking practice tests without an error log is like running a job without a punch list: you find the same problems again on the next walkthrough. An error log turns each miss into a specific next action and, after a few sets, shows you which kind of mistake you actually make. This guide gives you the template, the categories, worked examples of filled-in rows, and a weekly review routine. It is written for electrician candidates, but the template works for any trade exam on this site.
What an error log is for
Three things, in order of importance:
- Separating "did not know" from "knew but missed." These need different fixes. Knowledge gaps need reading; misreads and lookup failures need drills.
- Turning a miss into an action. "Review grounding" is not an action. "Re-read Table 250.122 and its notes, then redo questions 4 and 11 on Friday" is.
- Showing patterns. One miss on load calculations means little. Five misses that all happened at the unit-conversion step is a diagnosis.
The template
Use a notebook, a spreadsheet, or index cards. The columns matter more than the medium.
| Column | What to write | Why it is there |
|---|---|---|
| Date | When you took the set | Lets you see whether a category is shrinking over time |
| Source | Which test or topic quiz, and the question number | So you can redo the exact question later |
| Topic | Grounding, load calc, wiring methods, definitions, and so on | Groups misses by subject |
| Code reference | The article, section, or table that decides the answer | Builds your tab list and your lookup map |
| Error type | One of the six categories below | The most important column; it picks the fix |
| What I believed | One sentence, in your own words | Names the wrong idea so it can be replaced |
| What is true | One sentence, with the reference | The replacement |
| Next action | Something you can finish in under 20 minutes | Turns the miss into work |
| Recheck date | Two to seven days out | Forces a second attempt before you forget |
The six error types
| Type | Definition | The fix |
|---|---|---|
| Knowledge | You did not know the rule or concept | Read the topic page or code section, write a one-line summary, redo the question in three days |
| Misread | You knew the rule but answered a different question (missed minimum, NOT, dwelling, continuous) | Practice the three-pass read; see how to read exam questions |
| Lookup | Open-book exam: you could not find the section, or found the wrong one, in time | Drill the entry point for that article; see the NEC lookup routine |
| Setup | Calculation: wrong formula, missing factor, or wrong unit | Run the five-step checking routine on the question in writing |
| Arithmetic | Right setup, wrong number | Slow down at Step 4; redo the calculation with the calculator display written on paper |
| Changed answer | You had it right and switched | Only change an answer when you can name the specific fact that was wrong the first time |
Filled-in examples
These rows are original, made-up examples of what a filled-in log looks like. The question numbers are placeholders for whatever set you took; ExamsLib practice sets are assembled from a question bank, so the same number will not point to the same question every time. Notice that every "next action" is small and has a date. Code section numbers are from the 2023 NEC; write the numbers from the edition your exam uses.
Row 1. Source: (my set of Sept 3), question 7. Topic: grounding and bonding. Reference: Table 250.122 (2023 NEC). Error type: Lookup. What I believed: the equipment grounding conductor table was in Article 310 with the ampacity tables. What is true: it is in Article 250, and it is read by the rating of the overcurrent device, not the conductor size. Next action: tab Article 250, open the book to Table 250.122 ten times from a closed book. Recheck: Thursday.
Row 2. Source: load calculations topic checkpoint, question 3. Topic: load calculations. Reference: Article 220 (2023 NEC; Article 120 in the 2026 NEC), general lighting load. Error type: Setup. What I believed: the volt-amperes per square foot value could be used directly as amperes. What is true: VA must be divided by the system voltage to get amperes. Next action: redo the question writing the units on every line. Recheck: Saturday.
Row 3. Source: (my set of Sept 3), question 15. Topic: definitions. Reference: Article 100. Error type: Misread. What I believed: the question asked which item was required; it asked which was NOT required. What is true: read the trap word before the choices. Next action: on the next set, underline NOT/EXCEPT in every stem before reading choices. Recheck: next full set.
Row 4. Source: (my set of Sept 6), question 21. Topic: overcurrent protection. Reference: 210.20(A) (2023 NEC). Error type: Knowledge. What I believed: the 125 percent factor applies to every branch-circuit load. What is true: it applies to the continuous portion of the load; noncontinuous load is added at 100 percent, and the section has an exception for 100 percent-rated assemblies. Next action: write the rule as a one-line formula on an index card; redo questions 21 and 24 from that set. Recheck: Wednesday.
Row 5. Source: (my set of Sept 6), question 9. Topic: voltage drop. Reference: informational notes in Articles 210 and 215 (2023 NEC). Error type: Changed answer. What I believed: first pick was "recommended"; changed to "required" because it sounded more official. What is true: for general branch circuits and feeders the percentages in those informational notes are recommendations; specific installations have their own mandatory rules elsewhere. Next action: no change without a named fact. Recheck: next set, count changed answers.
The weekly review
Once a week, spend twenty minutes on the log itself, not on new questions:
- Count by error type. Write the six counts at the bottom of the page. The biggest count is next week's priority, whatever it turns out to be; the point of counting is to find out rather than assume.
- Count by code reference. Any article that appears three or more times gets a tab (where your exam allows tabs) and a fifteen-minute re-read.
- Do the rechecks that are due. Redo each question cold. If you miss it again, the next action was too small; make it bigger and push the recheck date out.
- Close rows. A row is closed when you have passed its recheck twice. Draw a line through it. Watching rows close is what keeps people logging.
Reading the pattern
After three or four practice sets the log usually tells one of these stories:
- Mostly misreads and changed answers. Your knowledge is fine; your exam technique is costing you. Slow down on the stem, speed up everywhere else.
- Mostly lookups. You know what the rule is about but not where it lives. Spend a week on navigation drills before doing more full sets.
- Mostly setup and arithmetic. Calculations are the gap. Work the calculation topics with the checking routine until the setup errors disappear; arithmetic errors usually go with them.
- Mostly knowledge, concentrated in one or two articles. Good news: that is the cheapest kind of gap to close. Read the matching topic page and the code article, then redo every logged question from that article.
When to stop logging and schedule the exam
An author's suggestion, not an official rule and not a validated predictor of passing: when three consecutive timed sets of questions you have not seen before, in a format and time limit that resemble your exam, score above your state's passing score, no new rows have been opened in the last two sets, and every open row has passed its first recheck, you have squeezed most of the value out of this kind of practice. Repeating a set you already know does not count; a familiar question tests memory of that question, not readiness. Scheduling while the material is fresh is reasonable, and your bulletin's eligibility rules govern when you actually can.
Start the log today
Take the free electrician practice test now and log every miss using the columns above before you look at anything else. The electrician study guide tells you which topic page to read for each code reference you write down, and the practice list has more sets for the rechecks.
Sources and verification notes
This guide is a study method. The example log rows mention specific code references (Table 250.122, Article 220, Section 210.20(A), the voltage-drop informational notes) and the 125 percent continuous-load rule as they stand in the 2023 NEC; those are from editorial knowledge and were not re-read in the code text for this revision, and the row texts say to use the numbers from your own edition. The question numbers in the rows are placeholders, not identifiers of questions in the ExamsLib bank. The readiness rule at the end is the author's suggestion, not an official standard or a validated predictor.
- NFPA 70, National Electrical Code, Article 90.5 (mandatory and permissive rules, informational notes)Checked September 18, 2026
- NFPA 70, 2023 NEC, Section 210.20(A) (branch-circuit overcurrent device rating: noncontinuous load plus 125 percent of continuous load; 100 percent-rated assembly exception)Section number and rule as known to the editorial team for the 2023 edition; the code text was not re-read in the free-access viewer for this revision. Confirm in your edition.
Written by the ExamsLib editorial team. Practice examples in this guide are original and are not official exam questions. Exam rules change; the candidate bulletin from your licensing authority is the final word. Found an error? Contact us.
