Experimentation in Scientific Research

An experimental approach to problem solving is only useful in scientific research laboratories.

• a.true
• b.false

A key aspect of the experimental method is that

• a.only experiments involve the use of controls.
• b.one or more variables are consciously manipulated.
• c.experiments are completed in research laboratories.
• d.one or more variables are observed.

A well-designed experiment to investigate the effect of increased CO₂ concentration on plant growth could include:

• a.exposing 100 plants to high CO₂ concentration.
• b.exposing 50 plants to high CO₂ concentration and 50 plants to zero CO₂ concentration.
• c.exposing 100 plants to normal CO₂ concentration and then later to high CO₂ concentration.
• d.exposing 50 plants to high CO₂ concentration and 50 plants to normal CO₂ concentration.

In the image that follows of Louis Pasteur's flasks, Figure 26 in the lower right corner represents

• a.a positive control.
• b.a negative control.
• c.the treatment group.
• d.a non-experimental flask.

Scientific research always makes use of only one methodology and never overlaps multiple methods.

• a.true
• b.false

A medical researcher is working to find a cure for diabetes. In the process of her research, she has identified a compound that she thinks might reduce the amount of insulin a diabetic patient needs each day. Her research team had recruited 300 test subjects and divided them into six groups: 1A, 1B, 1C, and 2A, 2B, 2C. None of the individuals will know what medications they are receiving. Which of the following groups is the control?

• Group 1A – receives 25 mg of the new compound along with their regular amount of insulin
• Group 1B – receives 25 mg of the new compound along with half of their regular amount of insulin
• Group 1C – receives 25 mg of the new compound along with a quarter of their regular amount of insulin
• Group 2A – receives 25 mg of a placebo and their regular amount of insulin
• Group 2B – receives 25 mg of a placebo and half of their regular amount of insulin
• Group 2C – receives 25 mg of a placebo and a quarter of their regular amount of insulin

• a.Group 1A
• b.Group 1B
• c.Group 2A
• d.Group 2C

In the same experiment described above, what is the independent variable?

• a.The new compound.
• b.The amount of insulin.
• c.The reaction of the patient.
• d.The placebo.

What is the dependent variable in the experiment?

• a.The amount of insulin.
• b.The compound.
• c.The reaction of the patient.
• d.The placebo.