Designing an experiment

A group of scientists genetically engineered a type of bean plant so it was naturally resistant to insect pests.  Which of these was most likely part of their original definition of the problem they wished to solve?

• Keep insects away from where people live
• Grow bean plants with less water
• Use fewer chemicals pesticides
• Store beans longer without fear of spoilage

Trina wanted to find out which of her two rubber balls could bounce the highest.  She took the first ball and dropped it onto the cement sidewalk.  She then dropped the second ball from the same height on the grass.  She recorded how high each ball bounced.  Her experiment could be improved by

• measuring the time it takes for each ball to reach its maximum height
• bouncing both balls on the same surface
• dropping the second ball from a higher position
• bouncing each ball a different number of times

Students are growing plants in the dark or in the light to see which grows better.  They put 3 seeds in the dark and 5 seeds in the light because they know seeds are more likely to dry out in the light. 
How could this experiment be improved?

• Put all plants in the light.
• Put all plants in the dark (where they sprout better)
• Put the same number of seeds in each container.
• put all the plants in the light so they grow better

Variables are parts of an experiment that change. When designing an experiment, scientists should test...

• using no variables
• with only one variable that changes
• with 2 variables
• with 3 or more variables

A testable prediction to what will be the outcome of a scientific experiment is called...

• a force
• organic matter
• soluability
• a hypothesis

Why is it important to test our hypothesis multiple times when designing our experiments?

• to find accurate data that supports scientific truth
• It helps fill up the time
• It looks impressive to have numbers that go along with the experiment
• Isaac Newton would be happy to see it.

A ball is placed at the top of a ramp. When released the ball rolls down towards the carpet surface. To see if the ball will roll further, we change the height of the ramp. What is the variable that was tested in this experiment?

• The use of different balls on the ramp
• The height of the ramp
• The surface of the carpet below the ramp.
• Changing the surface of the ramp.

A student is testing how a magnet causes different objects to move, by seeing how far away the magnet could be from an object. The student tested three different magnetic objects, on five different surfaces, multiple times. The students also used a blue magnet, a yellow magnet, and a green magnet. What did the students do wrong in testing their experiment?

• They didn't repeat their experiment a couple of times.
• They only had two things that were changing.
• They forgot to test something that was non-magnetic
• They had too many variables 

How do plants grow? 

• Testable
• Nontestable

How does the surface on which a car moves affect how fast it goes? 

• testable
• nontestable