Identifying Errors

Overview

This lesson helps you move from spotting that a result is wrong to explaining why it might be wrong and how the method could be improved. This is one of the most useful practical skills because every real investigation has limits.

What You Need to Know

• An error is something that makes a measurement less accurate or less reliable.
• Random errors cause readings to vary unpredictably, such as reaction-time differences or small changes in where you read a scale.
• Systematic errors shift results in the same direction each time, such as a balance not set to zero.
• An anomaly is a result that does not fit the pattern.
• Improvements should match the error. For example, repeats help with random error, while zeroing or calibrating equipment helps with systematic error.

How to Work Through It

1. Start by looking at a practical method and identifying where errors could enter.
2. Classify each error as random or systematic.
3. Match each error to a practical improvement.
4. Practise writing improvement statements that explain why the change would help.

Check Your Understanding

• Is the error random or systematic?
• Would repeating readings fix this problem, or is a different improvement needed?
• What makes a result an anomaly?
• Does your improvement explain how accuracy or reliability would increase?

Common Mistakes

• Saying “repeat it” for every improvement, even when the problem is systematic.
• Calling every unusual result an anomaly before checking the method or pattern.
• Describing the error but not giving a matching improvement.
• Using accuracy and reliability as if they mean exactly the same thing.

Next Steps

• Use the worksheet to practise matching errors to realistic improvements.
• Keep a short list of common practical errors for revision.