Accidental Errors Explained

In surveying and other measurements, errors can occur due to various reasons. Understanding these types of errors is crucial for accurate results. The question asks for another name for accidental errors.

What are Accidental Errors?

Accidental errors are unpredictable errors that occur randomly. They do not follow any specific pattern or rule and are usually small in magnitude. These errors happen despite taking all necessary precautions and using proper procedures.

Examples of sources of accidental errors include:

• Sudden variations in atmospheric conditions (like wind).
• Human limitations in precision when reading instruments.
• Minor disturbances at the observation point.

Due to their random nature, accidental errors can be positive or negative. When a large number of observations are taken under similar conditions, these positive and negative accidental errors tend to cancel each other out, making their cumulative effect small. Because they tend to compensate or balance each other over many readings, accidental errors are also known as compensating errors.

Comparison with Other Error Types

Let's briefly look at the other options provided to understand why they are different from accidental errors:

• Mistakes: These are not errors in the technical sense but are blunders caused by carelessness, misunderstanding, or fatigue. Examples include misreading a scale, transposing figures (e.g., writing 45 instead of 54), or setting up equipment incorrectly. Mistakes are usually large and can be detected and corrected through careful checks and repetitions.
• Systematic errors: These errors follow a definite pattern and occur under the same conditions in a consistent manner. They are caused by factors such as faulty equipment (e.g., a tape that is too long or too short), environmental conditions (like temperature affecting a steel tape), or personal bias of the observer. Systematic errors are cumulative if not corrected and tend to have the same sign (always positive or always negative) under specific conditions.
• Cumulative errors: This term often describes systematic errors because their effect accumulates over a series of measurements. Unlike accidental errors which tend to compensate, systematic errors add up, leading to a significant deviation from the true value if not eliminated or corrected.

Based on the nature and behavior of errors, accidental errors are characterized by their tendency to cancel out over multiple observations. This compensating nature is why they are also referred to as compensating errors.