1. Scientific Investigations

2. Unit 1 Lesson 2 Scientific Investigations
Testing, Testing, 1, 2, 3
What are some parts that make up scientific investigations?
Scientists investigate the natural world through experiments and observations.
An experiment is an organized procedure to study something under controlled conditions. 2

3. There are two types of observations:
An Observation is the process of obtaining information by using all of the 5 senses.
Sight
Smell
Hearing
Taste
Touch
There are two types of observations:
Qualitative
Quantitative

4. Observation
Ohh… This liquid is green and it is leaking from a brown can. I also smell it.
Ohh… This liquid is green and it is leaking from a brown can. I also smell something. smell it.

5. Qualitative Observations
Qualitative observations describe what we observe.
“Qualitative” = quality (descriptive)
These observations use adjectives to describe something.
Example: The flower has white petals.
Example: Mrs. Whittaker has brown eyes.

6. Quantitative Observations
Quantitative observations measure what we observe.
“Quantitative” = quantity (numerical)
These observations use numbers to measure something in a quantitative way.
Example: The flower has seven petals.
Example: Mrs. Whittaker has two eyes.

7. Which is better?
Both types of observations are valuable in science. In an experiment though, quantitative observations can be precisely and objectively compared.
Qualitative: The road is long. (describes)
Quantitative: The road is 5 km long. (measures)
Some things are easier to quantify than others. Scientists use innovative ways of turning qualitative into quantitative.

8. Which is better?
For example, someone might say that a dead fish is smelly.
It is hard to know just how smelly the fish is though.
To make this quantitative, the scientist could ask the person to rate the “smelliness” on a scale of 1-5.
This would then allow you to compare how smelly the fish is!

9. Inferences
Inferences are an explanation for an observation you have made.
They are based on your past experiences and prior knowledge.
Inferences are often changed when new observations are made.
Again, observations are information we gather directly through our five senses….inferences help explain those observations!

10. Inference
Based on my observations, I think that this can is old and is leaking a toxic substance.
Based on my observations, I think that this can is old and is leaking a toxic substance..

11. Here are some examples!
Observation: The grass on the school’s front lawn is wet.
Possible inferences:
It rained.
The sprinkler was on.
There is dew on the grass from the morning.
A dog urinated on the grass.
All of these inferences could possibly explain why the grass is wet. They are all based on prior experiences. We have all seen rain, sprinklers, morning dew, and dogs going to the bathroom.

12. Here are some examples!
Observation: The school fire alarm is going off.
Possible inferences:
The school is on fire.
We are having a fire drill.
A student pulled the fire alarm.
Again, these are all logical explanations for why the fire alarm is going off.

13. Now you try it!
Observation: A student is sitting in the main office.
Possible inferences: ?
Why might a student be sitting there?

14. Practice
What are some observations and inferences about the picture below?

15. What are some parts that make up scientific investigations?
Unit 1 Lesson 2 Scientific Investigations
What are some parts that make up scientific investigations?
Scientific investigations may also involve the use of models.
A model is a representation of an object or a system. 15

16. What are some parts that make up scientific investigations?
Unit 1 Lesson 2 Scientific Investigations
What are some parts that make up scientific investigations?
A hypothesis is a testable idea or explanation that leads to scientific investigation.
A scientist may think of a hypothesis after making observations or after reading findings from other scientists’ investigations.
Hypotheses must be carefully constructed so they can be tested in a practical and meaningful way.
Many hypotheses use the “if/then” statements. 16

17. What are some parts that make up scientific investigations?
A claim can also be used in experiments.
A claim is a statement that answers the question or problem you are investigating.
It may also be thought of as the viewpoint you will defend on the question or problem.
The evidence used to support a claim can include:
data from an experiment
literacy quote
expert testimony
A counterclaim is a claim that negates or disagrees with the original claim.

18. What are some parts that make up scientific investigations?
Unit 1 Lesson 2 Scientific Investigations
What are some parts that make up scientific investigations?
If an investigation does not support a hypothesis, it is still useful.
The information from the investigation can help scientists form a better hypothesis.
Scientists may go through many cycles of testing and analysis before they arrive at a hypothesis that is supported. 18

19. What are some parts that make up scientific investigations?
Unit 1 Lesson 2 Scientific Investigations
What are some parts that make up scientific investigations?
A variable is any factor that can change in a scientific investigation.
An independent variable is the factor that is deliberately manipulated.
A dependent variable changes as a result of manipulation of one or more independent variables (also known as the responding variable).
A controlled variable stays the same throughout the experiment and is not manipulated at all. 19

20. Amount of Water Given Daily Amount of growth after 4 days
Sample Experiment
Independent
Controlled
Dependent
Test Subject
Amount of Water Given Daily
Amount of light
Amount of growth after 4 days 1
10 mL
10 hours
2 cm 2
50 mL
2.5 cm 3
75 mL
3 cm

21. What are some parts that make up scientific investigations?
Unit 1 Lesson 2 Scientific Investigations
What are some parts that make up scientific investigations?
Data is information gathered by observation or experimentation that can be used in calculating or reasoning.
This information may be anything that a scientist perceives through the senses or detects using instruments.
During their investigations, scientists record all their observations, setup, and procedures, so that they will not forget anything. 21

22. What are some parts that make up scientific investigations?
Unit 1 Lesson 2 Scientific Investigations
What are some parts that make up scientific investigations?
Scientists analyze data to determine the relationship between the independent and dependent variables in an investigation.
Then they draw conclusions about whether the data support the investigation’s hypothesis. 22

23. Many Methods What are some scientific methods?
Unit 1 Lesson 2 Scientific Investigations
Many Methods
What are some scientific methods?
Scientists do not always use the same steps or same order of steps in every investigation.
They may even repeat some steps. 23

24. Collect and Organize Data Define a Problem or Ask a Question
Perform Experiment
&
Collect and Organize Data
Define a Problem or Ask a Question
Form a Hypothesis and Make a prediction
Indentify Variables
Interpret and Analyze Data and Information
Do Research &
Plan an Investigation
Draw and Defend the Conclusion

25. But what happens when the conclusion doesn’t support the hypothesis?

26. Collect and Organize Data The Problem or Question Remains the Same
Perform Experiment
&
Collect and Organize Data
The Problem or Question Remains the Same
Form a NEW Hypothesis and Make a prediction
Indentify Variables
Interpret and Analyze Data and Information
Do Research &
Plan an Investigation
Draw and Defend the Conclusion

27. Unit 1 Lesson 2 Scientific Investigations
High Quality
What are some characteristics of good scientific investigations?
Good scientific investigations share some important characteristics.
Scientific observations should be well-documented and have supporting evidence.
In an experiment, the variables should be controlled as much as possible. 27

28. What are some characteristics of good scientific investigations?
Unit 1 Lesson 2 Scientific Investigations
What are some characteristics of good scientific investigations?
Experiments should be repeated multiple times by the original investigator.
Scientific investigations should also be able to be replicated by scientists not involved with the original work.
Before publishing a study, scientific journals ask other scientists to review the article. This is called peer review. 28

29. How can you evaluate the quality of scientific information?
Unit 1 Lesson 2 Scientific Investigations
How can you evaluate the quality of scientific information?
The most reliable scientific information is published in scientific journals, but it is often difficult to understand.
Reliable books are written by scientists and others who are knowledgeable about a particular field.
Reliable Internet sources are government and academic web pages. Commercial web pages are often unreliable because they are trying to sell something. 29