How does a scientific investigation usually begin?
Someone makes an observation.
After a scientist makes an observation, she does something. What does she do?
Asks a question and collects data.
To find reliable answers to a question, a scientist does this.
Performs an experiment.
This is the use of the scientific methods to test a hypothesis.
Definition of experiment.
A hypothesis is:
A statement of what you think will happen in an investigation.
Studies living things:
When scientists can't do a controlled experiment, they can:
Do one of three types of investigations- models, surveys, and sampling.
A model is:
Objects or ideas that represent other things. An example would be testing car safety with computers or a clay car.
Asking people questions, then recording or analyzing answers. An example would be asking all the people at a picnic what they ate and drank if people were sick.
Collecting data by asking only some people at random questions. This would be asking some of the people at a picnic what they ate or drank. They would generalize the results to all the people there.
True or false: Scientists do the scientific methods in the exact same order each time.
True or false: Scientists may skip steps of the scientific methods.
Tell what step of the scientific methods is being used: IF I put lemon juice on a slice of apple THEN it will not turn brown, BECAUSE the juice keeps the apple from reacting to the air.
Tell what step of the scientific methods is being used: What happens if I leave an ice cube in the sun?
Something that can change a test is a:
A variable that "stands alone" like someone's age in an experiment would be an example of an/a:
A variable that depends on other factors. An example would be a test score because it would depend on how much you studied, if you were absent, etc.
True or false: A scientist should choose only one variable at a time to change so that it is a fair test.
A control group is:
A standard in which change is measured. An example would be giving one group of mice a vitamin and one group no vitamins and measuring any difference between the mice.
Deciding what materials to use is part of:
Making a plan to test a hypothesis.
An inference is:
Coming up with a conclusion based on our observations, data and using logic to connect ideas. An example would be: after taking data about plants, you can infer that plants grow less when given soda.
A conclusion is:
The last step of the method in which you look at all your data and use inferencing to tell if your data supports your hypothesis. An example would be: Nail polish dries faster if you spray Pam cooking spray on it, than if you leave it air dry.
True or false: In repeated trials, you change a variable each time and do the experiment a little differently each time, so that you can tell if your conclusion is valid (true).
True or false: It is not important if other scientists get the same results when doing experiments.