Scientific Investigations

What is a dependent variable?

• parts of the investigation the scientist keeps the same

• the variable that is measured in an experiment (data)

• the variable the scientist manipulates in an experiment

• to study using your five senses

Select the testable question.

• Does changing the amount of sunlight
  affect the growth rate of daffodils?

• Do cats or dogs make better house pets?

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

What is an independent variable?

• the variable that the scientist changes in an experiment

• a part of an experiment that stays the same

• a prediction of what will happen in an experiment

• the variable that is measured in an experiment

Read the hypothesis: If students regularly play chess, then they will be able to solve logic puzzles faster.

What is the dependent variable?

• time it takes to solve logic puzzles

• how often students play chess

A student asked, "what effect does using plant food have on plant growth?"

What statement is the best hypothesis for this experiment?

• If the plant food is expired, then it will smell bad.

• If the plant is left in the sun, then it will grow taller/faster.

• If the plant is not watered, then it will die.

• If plant food is used, then plants will grow taller/faster.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

A student asked, "do fish live longer if their tank is cleaned once a week?"

What statement is the best hypothesis for this experiment?

• If an aquarium is cleaned once a week, then the tank will be cleaner.

• If an aquarium uses fresh glacier water, then the fish with live longer.

• If an aquarium is cleaned once a week, then the fish will live longer.

• If the fish in the aquarium have filtered water, then they will live longer.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-4

A ___________ is a prediction of what will happen in an experiment.

• inference

• observation

• hypothesis

• constant

Ms. Lanctot wanted to conduct an experiment to measure the effect of different brands of flour on the time it takes bread to rise.  What measurement tool should she use to collect the data in this experiment?

• meter stick

• stopwatch

• balance

• graduated cylinder

Select the non-testable questions. There are two answers.

• Does the changing the shape of a
  kite affect its ability to fly?

• Why is the sky blue?

• Why do some tree logs burn longer than others?

• Does the temperature of the classroom
  affect student performance?

After reading the procedure below, which items are constants in the investigation? There are two constants.

• number of Mentos

• type of soda

• soda left in bottle

• amount of soda