Scientific Method & Experimental Design
This is the variable that the scientist changes on purpose during an experiment.
What is the independent variable.
After Alexis tested magnets of different sizes, she should do this before making a final conclusion.
What is conduct more trials? (repeat the experiment)
When a scientist repeats their own experiment (trials).
What is repeat/repetition.
A scientist changes the amount of fertilizer given to plants and measures plant height. This is the dependent variable.
What is plant height?
A scientist tests plant growth under different light conditions. Plant A grows 10 cm, Plant B grows 15 cm, and Plant C grows 20 cm. Which plant showed the greatest growth?
What is Plant C?
This variable changes as a result of the test and is measured by the scientist.
What is the dependent variable.
Evidence that matches a hypothesis does not prove it; it does this instead.
What is support the hypothesis?
When a scientist conducts another scientist's experiment.
What is replicate/replication.
In Devin's crystal experiment, the scientist changes the temperature of the jars. This is the independent variable.
What is temperature?
A magnet experiment shows: Small magnet = 8 paperclips, Medium magnet = 15 paperclips, Large magnet = 22 paperclips. What trend does the data show?
What is larger magnets attract more paperclips?
In Carmen's flower experiment, phosphate was added to some plants to test its effect on growth. Identify the independent variable.
What is phosphate?
Pat and Terry thought hummingbirds liked yellow feeders best, but the red feeder had the least food left. What can be said of the hypothesis?
What is NOT supported by the results.
An astronomer investigating a possible new comet should keep these to make a valid scientific conclusion.
What are detailed observation records?
In an experiment, these are the factors kept the same so the test is fair.
What are controlled variables?
A graph shows plant height increasing from 5 cm to 15 cm over three weeks. What trend is shown?
What is an increase in plant growth over time?
Repeating an experiment several times helps improve this.
What is accuracy/reliability.
When Julie's data rejected her hypothesis, she should use the data to create new questions and possible ______.
What are new experiments?
To test whether temperature affects crystal growth, Devin should place some jars in the refrigerator and others at room temperature so he can compare this factor/variable.
What is temperature?
If a scientist changes both the amount of fertilizer and the amount of water at the same time, it becomes difficult to identify this.
What is the cause of the results? (or identify the independent variable)
A student records these boiling points: Water = 100°C, Salt Water = 101°C, Saltier Water = 102°C. What conclusion is supported?
What is adding salt increases the boiling point?
Students tested cola, lemon juice, milk, and soap. The best way to improve accuracy is to do this.
What is test each material multiple times? (repetition)
When new evidence does not support a hypothesis, scientists should do this.
What is form a new hypothesis and test it?
Scientists often use computer simulations of storms because a controlled experiment would have too many of these.
What are uncontrollable variables?
In a pH experiment, students use 100 mL of each liquid sample. The volume of liquid is a ______.
What is a constant (controlled variable)?
Scientists look for patterns, trends, and relationships in tables and graphs so they can do this.
What is draw evidence-based conclusions?