USPS Error Detection Test Detecting Sorting Errors Questions and Answers 1 — Questions and Answers
Question 1: A mail handler is verifying tray routing numbers. The number printed on the tray label is '4638 1120 5591' and the number displayed on the sorting machine's screen is '4638 1120 5951'. How many digits are in error?
- One
- Two (Correct answer)
- Three
- None
Correct answer: Two
Comparing the two numbers, '4638 1120 5591' and '4638 1120 5951', the first eight digits match perfectly. The error occurs in the last group of four digits. The '5' became a '9', and the '9' became a '5'. These are two distinct digit errors.
Question 2: A data entry clerk is processing a batch of ZIP codes. An error occurs where the intended ZIP code '90210' is entered as '9021'. Which of the following best describes this type of error?
- Transposition
- Substitution
- Omission (Correct answer)
- Insertion
Correct answer: Omission
An omission error occurs when a piece of data, in this case, the final digit '0', is left out or omitted from the entry. A transposition is when adjacent digits are swapped, a substitution is when a wrong digit replaces a correct one, and an insertion is when an extra digit is added.
Question 3: Which of the following pairs of alpha-numeric sorting codes is an exact match with zero errors?
- FCM-LTR-MACH-AADC 789 / FCM-LTR-MACH-AADC 798
- PRS-FLTS-WKG-CR-RTS 5 / PRS-FLTS-WKG-CR-RTS 5 (Correct answer)
- STD-MKT-LTR-BC-WKG / STD-MKT-LTR-BC-WKG-FX
- PER-PKG-SVC-NDC-LBL / PER-PKG-SVC-NDC-LBLS
Correct answer: PRS-FLTS-WKG-CR-RTS 5 / PRS-FLTS-WKG-CR-RTS 5
This question requires a careful character-by-character comparison. The pair 'PRS-FLTS-WKG-CR-RTS 5' is identical to itself. The other pairs contain errors: a number transposition (789/798), an extra abbreviation (-FX), and an extra letter (LBL/LBLS).
Question 4: An automated scanner reads a smudged ZIP+4 code. The correct code is '55407-1982', but the system interprets it as '55407-19B2'. This type of error, where a number is misread as a letter, is best classified as a:
- Transposition error
- Omission error
- Formatting error
- Substitution error (Correct answer)
Correct answer: Substitution error
A substitution error occurs when an incorrect character replaces the correct one. In this scenario, the scanner incorrectly substituted the number '8' with the letter 'B' due to the smudge. This is a common issue with Optical Character Recognition (OCR) systems.
Question 5: A clerk is performing a quality check on a sequence of five tracking numbers. Compare the 'Entered' sequence to the 'Correct' sequence below. What is the total number of individual digits in error across the entire set? Correct: 4401-8827-53; Entered: 4401-8287-53
- One
- Three
- Four
- Two (Correct answer)
Correct answer: Two
By comparing the 'Correct' number (4401-8827-53) with the 'Entered' number (4401-8287-53), we can see the first block '4401' and the last block '53' are correct. In the middle block, the correct '8827' was entered as '8287'. The second '8' was incorrectly entered as a '2', and the '2' was incorrectly entered as an '8'. This specific type of error, a swap of adjacent characters, is called a transposition and results in two digits being incorrect.
Question 6: During mail processing, an address is flagged with the error code 'Insufficient Address'. Which of the following is the most likely cause for this specific error?
- The addressee has filed a change-of-address form.
- The postage paid is less than the required amount.
- A critical piece of the address, like a suite or apartment number, is missing. (Correct answer)
- The mailpiece exceeds the maximum weight limit for its class.
Correct answer: A critical piece of the address, like a suite or apartment number, is missing.
The 'Insufficient Address' error code is used by the USPS when a mailpiece cannot be delivered because a necessary part of the address is missing or incomplete. This commonly includes a missing apartment, suite, or floor number which prevents the carrier from finding the specific delivery point.
A mail handler is verifying tray routing numbers.
The number printed on the tray label is '4638 1120 5591' and the number displayed on the sorting machine's screen is '4638 1120 5951'.
How many digits are in error?