SCIENCE
ENVIRONMENTAL SCIENCES
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
A control group is given the experimental treatment.
|
|
|
A single variable is tested.
|
|
|
A control is used.
|
|
|
A single variable is tested and a control is used.
|
Detailed explanation-1: -Good experiments have two essential characteristics: a single variable is tested, and a control is used. The variable is the factor that changes in an experiment in order to test a hypothesis.
Detailed explanation-2: -As long as the experiment is repeated a sufficient number of times, it does not matter how many variables are used. Yes, an experiment should test only one variable at a time. This ensures that the experimental outcome is clearly due to one identifiable factor.
Detailed explanation-3: -In a controlled experiment, all extraneous variables are held constant so that they can’t influence the results. Controlled experiments require: A control group that receives a standard treatment, a fake treatment, or no treatment. Random assignment of participants to ensure the groups are equivalent.
Detailed explanation-4: -Provides unbiased estimates of the factor effects and associated uncertainties. Enables the experimenter to detect important differences. Includes the plan for analysis and reporting of the results. Gives results that are easy to interpret. More items •29-Aug-2012