Vocabulary
Define Hypothesis
An educated guess or prediction
Define Control group.
A control group is an element that is not changed throughout an experiment.
The one factor that a scientist changes during an experiment.
Independent Variable
Is it okay if I fill out only a tiny part of a graph or do I need to fill out the entire graph?
The entire graph!
What is a placebo?
A "sugar pill" that seems real.
Define observation
Using your 5 senses to gather information
Create a hypothesis.
Do you think that talking to your plants every day will make them grow more?
I do/don't think that talking to your plants every day will make their increase/decrease height because ___________.
The higher the temperature of the water, the faster the egg will boil.
Identify the independent and dependent variables.
IV: Temperature
DV: Time
What are the things you need to include on a graph?
Title, Scale, Axes Labels, Data Points, etc.
Name 2 characteristics of a good experiment.
1. Can be repeated the same way and get the same results.
2. Tests only one independent variable.
3. Experiment follows ethical and legal standards.
4. Have a big sample size.
5. Tests hypothesis to show wether its right or wrong.
6. Are performed for long periods of time.
7. Are Peer-reviewed.
8. It is objective.
A scientific procedure that tests a hypothesis.
Experiment
Using the hypothesis:
If acid rain is in water, then the fish population will increase.
Identify the IV and DV.
IV: Acid rain amount
DV: Fish population
You water three sunflower plants with saltwater. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. After a two-week period, the height is measured.
Identify the IV and DV
IV: Concentration of salt
DV: Height
True or false?
Your scale has to have a consistent interval.
True! Your scale should go up by 1s, 2s, 5s, 10s, 20s, etc.
What is more trustworthy - a theory or a hypothesis?
Theory! It's made by scientists!
What is a theory?
An explanation of natural events supported by stron evidence.
What things do you need to include when creating a hypothesis?
Independent Variable, Dependent Variable, & Reason
If IV... then DV.... because...
Research Question: Do tomatoes grow fastest under fluorescent, incandescent, or natural light?
What are the independent and dependent variables?
IV: Light Source
DV: Tomato Plant Height
The independent variable goes on the ____ axis.
X-axis
In a controlled experiment, how many independent variables can be tested at one time?
Only 1!
Define independent variable and dependent variable.
Independent Variable: the thing that changes in the experiment
Dependent Variable: the variable being tested and measured in an experiment
You water three sunflower plants with saltwater. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. After a two-week period, the height is measured.
What is the CG and hypothesis?
CG: Pure water Plant
Hypothesis: If you increase/decrease the amount of saltwater, then the plant height will increase/decrease because ...
Ben makes five paper helicopters with different wing lengths. He drops them the same way from a height of two meters for five trials each. He records the amount of time it takes for each helicopter to fall to the ground.
What are the independent, dependent variables and control group?
IV: Wing Length
DV: Amount of time it takes for each helicopter to fall to the ground
CG: He drops them the same way from a height of two meters
Why are graphs useful?
Visually organize data contained in a table.
Allows you to easily observe trends.
True or false?
The purpose of an experiment is to prove the hypothesis true
False, the purpose of an experiment is to test if the hypothesis is true or false