Scientific Method & Experimentation

In a science experiment, John is testing the effect of different types of soil on plant growth. He uses the same type of plant, the same amount of water, and the same amount of sunlight for all groups. What are these variables called that remain the same for all groups?

• Independent

• Dependent

• Control

• Constant

Identify the problem with this experiment:  
A scientist thinks that flatworms swim faster if they are in salt water.  So he drops them in salt water and finds that they do swim very fast.  He concludes that salt water makes flatworms swim fast.  

• No independent variable
• Too many independent variables
• No control group
• No experimental group

Why is the statement "swimming is the coolest sport" a bad hypothesis?

• it's definitely not true

• basketball is the best sport

• it is opinion based and not testable

• not everyone can swim

In an experiment to discover which brand of bug spray does best at preventing mosquitoes bites, the brand of bug spray is the -

• control

• independent variable

• constant

• dependent variable

What is the first step in the scientific method?

• analyze data

• draw conclusions

• perform and experiment

• observe and recognize a problem

An experiment is conducted to test the hypothesis that a certain type of houseplant grows best when exposed to exactly four hours of sunlight per day. Which is the dependent variable?

• hours of sunlight

• growth of plant

• type of soil

• amount of water

In an experiment to determine which bug spray works best to keep mosquitoes from biting, what is the dependent variable?

• the cost of the spray

• the place where you conduct the experiment

• the amount of spray

• the number of bug bites

Experiments measure how changing the __________variable affects the __________ variable.

• controlled, other

• dependent, independent

• primary, secondary

• independent, dependent

A hypothesis is a prediction or explanation that can be -

• researched

• tested by experimentation

• proven

• modeled

Which statement is NOT true?

• An experiment is a failure if the data does not support the hypothesis.

• An experiment should have only one independent variable.

• More trials of an experiment will provide more reliable results.

• All factors other than the independent variable should be constant.