Unit 10 — The Scientific Method and Scientific Investigation

Welcome to Grade 5 Science!

Science is a way of learning about the natural world through careful observation, questioning, experimentation, and evidence.

Scientists do not simply guess.

They collect information, test ideas, analyze results, and share their discoveries with others.

Today you will learn how scientific investigations are designed and carried out.

What Is Science?

Science is the systematic study of the natural world.

Scientists investigate questions about:

• living things
• Earth
• space
• matter
• energy
• weather
• forces
• technology

Science is always based on careful observation and evidence.

Asking Questions

Every scientific investigation begins with a question.

Good scientific questions are:

• clear
• specific
• testable
• based on observation

Examples include:

• Which soil helps plants grow fastest?
• Does sunlight affect evaporation?
• Which materials conduct electricity best?

A well-written question guides the entire investigation.

Forming a Hypothesis

A hypothesis is a testable prediction.

It is not simply a guess.

A hypothesis is based on what is already known.

Example:

"If a plant receives more sunlight, then it will grow taller because sunlight provides energy for photosynthesis."

A good hypothesis can be tested through investigation.

Designing an Experiment

A fair experiment changes only one factor at a time.

Scientists identify:

• the question
• the hypothesis
• the materials
• the procedure
• the observations
• the conclusions

Keeping conditions consistent helps produce reliable results.

Variables

Experiments often include three types of variables.

Independent variable

The factor that is intentionally changed.

Dependent variable

The factor that is measured or observed.

Controlled variables

Conditions that remain the same so the test is fair.

Identifying variables helps scientists design accurate experiments.

Collecting Data

Scientists gather information carefully.

Data may include:

• measurements
• observations
• counts
• photographs
• drawings
• tables
• graphs

Accurate data lead to trustworthy conclusions.

Drawing Conclusions

After collecting data, scientists ask:

• Did the results support the hypothesis?
• What patterns appeared?
• Were there unexpected results?
• Could the investigation be improved?

Sometimes a hypothesis is supported.

Sometimes it is not.

Both outcomes provide valuable knowledge.

Communicating Results

Scientists share discoveries through:

• reports
• presentations
• graphs
• scientific journals
• diagrams

Sharing results allows others to repeat experiments and build on previous discoveries.

Science advances through collaboration and open communication.

Activity

Design a simple experiment.

Include:

• a scientific question
• a hypothesis
• the variables
• materials
• procedure
• data table
• conclusion

Explain how you would make the investigation fair.

Practice

Answer these questions.

What is science?

What makes a question testable?

What is a hypothesis?

What is the independent variable?

What is the dependent variable?

Why are controlled variables important?

Review

Today you learned:

• science uses evidence to understand the natural world
• investigations begin with thoughtful questions
• hypotheses are testable predictions
• experiments should be fair and carefully controlled
• accurate data lead to reliable conclusions
• scientists communicate discoveries so others can learn from them

The scientific method helps people investigate questions, solve problems, and make new discoveries.

Looking Ahead

Next we will explore matter, atoms, molecules, and chemical changes, learning how the materials around us are organized and how they change.