Experimental Design and Bias Quiz

What is an independent variable in an experimental study?

• The variable that is changed or manipulated

• The variable that is measured in the experiment

• The variable that is not relevant to the experiment

• The variable that remains constant throughout the experiment

What is a dependent variable in an experimental study?

• The dependent variable is the variable that is manipulated by the researcher.

• The dependent variable is the variable that is not affected by the independent variable.

• The dependent variable is the variable being measured or tested in an experiment.

• The dependent variable is the variable that remains constant in an experiment.

How does the experimental group differ from the control group?

• The experimental group is not studied, while the control group is the focus of the research.

• The experimental group receives a placebo, while the control group receives the actual treatment.

• The experimental group receives the treatment or intervention being studied, while the control group does not receive the treatment.

• The experimental group is not given any instructions, while the control group follows a strict protocol.

When experimenting with the growth of a plant, a scientist tested two different fertilizers (one with higher PH and one with lower PH). They use the same type of plant, equal light, and equal water. What type of variable is the fertilizer?

• Dependent

• Independent

• Control

• Compound

Suzie became interested in insulation while her parent’s new house was being built. She decided to determine which insulation transferred the least heat (i.e., kept an object cold). She filled each of 5 jars half-full with cold water. She sealed each jar with a plastic lid.Then she wrapped each jar with a different kind of insulation. She put the jars outside in direct sunlight for 8 hours. Later, she measured the temperature of the water in each jar. What is the independent variable?

• The type of insulation

• The temperature of the water

• Number of houses

• The amount of sunlight

Suzie became interested in insulation while her parent’s new house was being built. She decided to determine which insulation transferred the least heat (i.e., kept an object cold). She filled each of 5 jars half-full with cold water. She sealed each jar with a plastic lid.Then she wrapped each jar with a different kind of insulation. She put the jars outside in direct sunlight for 8 hours. Later, she measured the temperature of the water in each jar. What is the dependent variable?

• The type of insulation

• The temperature of the water

• Number of houses

• The amount of sunlight

Can pleasant aromas help a student learn better? Two researchers believed that the presence of a floral scent could improve a person's learning ability in certain situations. They had 22 people work through a pencil-and-paper maze 6 times. Three of the times they wore a floral-scented mask and three times they wore an unscented mask. The order of the trials was random. Testers measured the length of time it took subjects to complete each of the six trials. This study is:

• a convenience sample
• an oberservational study
• an experiment, but not double-blind
• a double-blind experiment

In order to perform an experiment using 60 members of a gym, I first divide the list of members into men and women because I feel that the results will be different based on gender. I then randomly choose 30 men and 30 women. I assign half of the men to the treatment group and half to the control group. I repeat this procedure with the women. This is an example of a:

• randomized comparative design
• blocking design
• matched pairs design
• double blind simple random sample

Explain the concept of non-response bias in data collection techniques.

• Non-response bias is the bias that occurs when the respondents who do participate in a survey or study are randomly selected from the population.

• Non-response bias is the bias that occurs when the respondents who do not participate in a survey or study differ from those who do participate.

• Non-response bias is the bias that occurs when the respondents who do participate in a survey or study do not differ systematically from those who do not participate.

• Non-response bias is the bias that occurs when the respondents answer in a different way to appeal to the researcher.

A political polling group is interested in learning about the proportion of registered voters who favor a particular candidate for mayor. Which of the following sampling plans may have introduced bias?

• Individuals were selected randomly to participate from a list of registered voters.

• Every 50^th person on a list of registered voters was contacted and asked to identify who they would vote for in the upcoming election.

• A list of registered voters was first separated into two lists—one of males and one of females. Then individuals were selected at random from each of the two lists.

• A survey was mailed to all registered voters and those who returned the survey make up the sample

• None of the above sampling plans creates the potential for bias.