Error detection — what does parity checking excel at? Select the statement that best describes the capability of parity for detecting transmission errors.

Introduction / Context:
Parity bits provide a simple, low-overhead method for error detection in digital communication. They indicate whether the number of 1s in a code word is even or odd, enabling detection of many, but not all, error patterns.

Given Data / Assumptions:

• Single parity bit appended per word
• Either even or odd parity scheme

Concept / Approach:
With parity, any single-bit flip toggles the overall parity, making the error detectable. However, two-bit errors restore the original parity in an even-parity scheme, escaping detection. Thus, parity is primarily useful for single-bit error detection, not correction or multi-bit reliability guarantees.

Step-by-Step Reasoning:

Verification / Alternative check:
Consider a word with even count of 1s using even parity. Flipping two bits keeps the 1-count even. The receiver sees correct parity and accepts the frame, demonstrating the limitation.

Why Other Options Are Wrong:

• Not suitable for single-bit errors: false—this is the core strength of parity.
• Detecting and correcting: parity alone does not correct errors.
• Best for double-bit errors: parity generally misses even-numbered bit flips.
• Detects any even-number errors: incorrect; even-numbered flips are exactly what parity can fail to detect.

Common Pitfalls:

• Overestimating parity as an error-correcting code; it is detection-only and limited.

Final Answer:
Parity checking is best suited for detecting single-bit errors in transmitted codes.