Scientists often repeat investigations several times. Give two reasons why.
How to approach this question
Think about the reliability and accuracy of scientific data. What problems can occur with a single measurement? What can you do with multiple measurements that you can't do with just one? List two distinct advantages of repeating an experiment.
Full Answer
1. To identify and remove anomalous results.
2. To calculate a more reliable mean.
Repeating investigations is a cornerstone of the scientific method for several reasons:
1. **Identifying Anomalies:** With multiple readings, it becomes possible to spot anomalous results – readings that do not fit the pattern. These can be caused by errors and can be excluded from calculations to avoid skewing the data.
2. **Calculating a Reliable Mean:** A mean (average) calculated from several readings is more likely to be close to the true value than a single measurement. This increases the reliability and precision of the results.
3. **Checking Repeatability:** If the scientist can repeat the experiment and get similar results, it shows the method is repeatable and the results are not a one-off fluke. If other scientists can do it, the results are reproducible.
Common mistakes
✗ Giving two very similar reasons, e.g., "to make it reliable" and "to make it accurate". While related, try to give distinct points like identifying anomalies and calculating a mean.
✗ Vague answers like "to get better results". Explain *how* the results are made better.
Expert