1. 5th Grade Investigation and Experimentation Skills

2. Variables
Variables
Something in the experiment that will change. Vari means to change.
In an experiment, the scientist deals with 3 types of variables.
1) Independent variable
2) Dependent variable
3) Controlled variables
To make an investigation scientific you must have an independent variable, a dependent variable, and controlled variables

3. Independent Variables
The variable that is purposefully changed (scientist will change it)
Can have only ONE in an investigation
Examples: amount of water, time, mass, temperature, amount of sunlight

4. Dependent Variable Dependent Variable
The variable that changes in response to the independent variable (usually measured or recorded in an investigation)
Examples: time it takes to evaporate, bounce height of the ball, distance traveled, change in plant height

5. Controlled variables Controlled variables
Things that are kept the same throughout the entire investigation
Examples: same location, same temperature, same conditions

6. Maria grew four plants in an experiment about plant growth
Maria grew four plants in an experiment about plant growth. The table below shows the design and results of Maria’s experiment.
You can see that Maria has 4 plants. She is watering all plants the same, and all the plants are receiving the same amount of plant food every day. These are called the CONTROLLED variables.
Each plant receives a different amount of sunlight each day. This is the INDEPENDENT variable because it is the variable that is being changed.
Maria is measuring the height of the plant at the end of the experiment. This is the DEPENDENT variable because it is the variable being measured.

7. Review Question # 1
Carlos put identical daisies on the windowsill next to each other. They both received 200 mL. of water daily. One plant received 10 mL. of fertilizer every day and the other did not.
What is the independent variable in Carlos’ experiment?
A the growth of the flower
B the amount of water
C the addition of fertilizer
D the amount of sunlight

8. Answer Question # 1
C The independent variable is the variable that is being changed in the experiment. In Carlos’ experiment, only one plant is receiving the fertilizer, so the addition of fertilizer is the independent variable. The growth of the flower is being measured and is the dependent variable. The amount of water, amount of sunlight, and type of plant are all the same and are all controlled variables.

9. Steps of the Scientific Investigation
Five Steps to the Scientific Investigation
Scientists follow the steps of the scientific investigation during an experiment
Five Steps:
Problem Question
Hypothesis
Procedure/Experiment
Results/Analysis of the Data
Conclusion

10. Problem Question
Problem Question – what we are trying to find out/ research
Must include the independent variable and dependent variable
Example: How does the amount of sunlight affect the growth of the plant?
In this example, amount of sunlight is the independent variable and growth of the plant is the dependent variable.

11. Review Question # 2
Which of the following questions is testable in a scientific investigation?
A Are dogs better pets than cats?
B Are dogs happy when they are walked?
C Are cats more active at night than during the day?
D Are cats easier to take care of than dogs?

12. Answer Question # 2
C A testable question is one that you can actually collect data for. Choices A, B and D are all opinions. How would you test that the animal is better, happier, or easier to take care of? However, you could test to see if cats are more active than dogs at night by observing both animals during the night and collecting data for what you observe.

13. Hypothesis Form a Hypothesis
Hypothesis: an educated guess that is tested over and over again.
Gives a solution to the problem question
Tells why your solution will work
Example: If the amount of sunlight increases, then the height of the plant will increase because I know that my plant at home always grows more when it is in the sun a lot.

14. Procedure/Experiment
Contains all information to perform the experiment: independent variable, dependent variable, controlled variables, materials, and supplies
The procedure might include diagrams, drawings of the experiment set-up, and steps listed with numbers.

15. Results/Analysis of the Data
Results are presented in charts, data tables and graphs
Results include data that is your opinion, like color change or odor.
It also includes data that is measured (time, measurement of distance, mass, temperature, and height)
Must include all data from the experiment

16. Conclusion
Interpret the data – was your hypothesis supported by the data?
List any sources of error
List any changes you would make the next time you conduct the experiment

17. Review Question # 3
During the experiment, Carlos wrote on his lab sheet, “I think the plant getting the fertilizer will grow more because my plants at home always grow more when I put fertilizer in them.”
This statement is an example of:
A a conclusion
B results
C an observation
D a hypothesis

18. Answer Question # 3
D A hypothesis is a guess that is tested. Carlos is stating what he thinks will happen and why. He is not stating a conclusion, what he learned. He is also not stating results, the data he collected during the experiment. Carlos is also not stating an observation, what he saw during the experiment.

19. Review Question # 4 Five Steps in an Investigation:
a) Procedure/Experiment
b) Hypothesis
c) Problem Question
d) Conclusion
e) Results/Analysis of the Data
George is going to conduct a scientific investigation. In what order should George follow the steps listed above?
A b d e a c
B c b a e d
C a b c d e
D c a d b e

20. Answer Question # 4
B The five steps of the scientific method in order are:
Problem Question
Hypothesis
Procedure/Experiment
Results/Analysis of the Data
Conclusion

21. Review Question # 5
The table shows the time it took to freeze plain water and water with different amounts of salt. According to the table:
A   water with more salt takes longer to freeze
B   freezing rates are the same in plain and salt water
C   plain water takes longer to freeze
D   both the water with 5 g salt, and the water with 10 g of salt, froze at the same rate

22. Answer Question # 5
A As more salt is added to the water, it takes longer to freeze. This is why salt is put on icy roads. The outside temperature has to be extremely low for the road to freeze because the salt lowers the freezing point of the water on the road.

23. Review Question # 6
The graph shows how many individuals were found in a beetle colony. How many more beetles than mealworms were found in this colony? A   5 B   8 C   14 D   32

24. Answer Question # 6
B According to the graph, there are 20 beetles and 12 mealworms. Therefore, there are 8 more beetles (20-12=8)

25. Review Question # 7
A scientist was studying a mammal population. The data table shows some of her results.
Which pie chart represents the information in the table?

26. Answer Question # 7
C Out of 205 individuals in the population, about half of them, 104, are juveniles. The pie chart should show the juvenile part of the chart being half, and males being slightly less than females.

27. Review Question # 8
Elaine wants to measure the volume of a large pitcher of lemonade. Which units should Elaine use?
A liters
B grams
C meters
D degrees

28. Answer Question # 8
A The volume of liquids is measured in units like liters, milliliters, quarts, and pints.