Experimental Design Quiz

What is a null hypothesis in experimental design?

• A statement that predicts a positive outcome

• A statement that predicts no effect or relationship

• A statement that predicts a negative outcome

• A statement that predicts multiple outcomes

Which of the following is a key component of experimental design?

• Random guessing

• Explanatory hypotheses

• Ignoring variables

• Avoiding controls

Tags

NGSS.MS-PS2-2

NGSS.MS-ETS1-4

What role do controls play in an experiment?

• They introduce new variables

• They ensure the experiment is biased

• They help isolate the effect of the independent variable

• They are unnecessary in scientific research

What is an explanatory hypothesis?

• A question about the relationship between variables.

• A testable, educated prediction about the relationship between variables.

• A random guess about scientific phenomena.

• A statement without any scientific basis.

Tags

NGSS.MS-LS1-5

Which of the following is NOT true about an explanatory hypothesis?

• It is a question.

• It is a statement.

• It explains the expected relationship between variables.

• It uses biological reasoning.

Tags

NGSS.MS-LS1-4

NGSS.MS-LS2-4

NGSS.MS-LS4-4

What is the correct format for writing an explanatory hypothesis?

• As a question that explores various possibilities.

• As a direct scientific claim that explains the expected relationship between variables.

• As a narrative story about scientific experiments.

• As a list of unrelated scientific facts.

What is the primary purpose of a null hypothesis (H₀) in scientific research?

• To predict a significant effect or relationship

• To serve as the default assumption tested against

• To confirm the explanatory hypothesis

• To ensure a positive outcome in experiments

Which of the following statements best describes a null hypothesis?

• It predicts a significant effect between variables

• It is the same as the explanatory hypothesis

• It predicts no relationship or effect between variables

• It is used to prove a scientific theory

A group of students designs an experiment to test whether different salt concentrations affect the germination rate of radish seeds. They place seeds in petri dishes with 0%, 2%, and 5% salt solutions and record the percentage of seeds that germinate after 7 days.

Which of the following is the best null hypothesis for this experiment?

• ncreasing salt concentration decreases the germination rate of radish seeds.

• Salt concentration has no effect on the germination rate of radish seeds.

• Seeds in 0% salt solution will germinate at a higher rate than seeds in 5% salt solution.

• Salt concentration influences how many radish seeds germinate.

Tags

NGSS.MS-LS2-1

What is the purpose of a control group in an experiment?

• To receive the treatment being tested

• To ensure all conditions are different

• To isolate the effect of the independent variable

• To introduce new variables

Tags

NGSS.MS-PS2-2