Year 8 Science · Unit 4 · Lesson 12

Evaluating Data Quality

Foundation Worksheet

Name
Date
Class

Learning Goals

Warm Up

Sort it!

Each feature below relates to an investigation design. Write each item into the correct column: Improves data quality or Reduces data quality.

3 repeated trials for each condition Only 1 measurement per condition Controlled variables kept the same Not zeroing the balance before weighing Using a calibrated thermometer No control group in the experiment Randomly selecting participants Cherry-picking only results that support your hypothesis Recording and investigating anomalous results Testing a very large range of conditions

Improves data quality

Reduces data quality

Your Turn

Fill the gap

Choose the correct word from the word bank to complete each sentence about data quality.

reliability validity sample size controlled trial peer review bias representative credible

When scientists repeat an experiment multiple times, each repetition is called a . Consistent results across all repetitions gives confidence in the of the data. A systematic distortion that pushes data in a particular direction is called . An investigation has good if it actually measures what it claims to measure, with all variables except the independent variable kept . A sample that reflects the whole population is called a sample. When more data points are collected, the is larger and conclusions are more trustworthy.

Show What You Know

1. Explain in your own words the difference between reliability and validity. Can an investigation be reliable but not valid? Give a short example.

Recall 2 marks

2. Why is it important to identify and investigate anomalous results rather than simply removing them from your data?

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?

HSCScience · Year 8 Science · Unit 4 · Lesson 12 · Foundation Worksheet