A controlled experiment is one in which:
Options
- AA. There are at least two groups, one of which does not receive the experimental treatment.
- BB. The experiment is repeated many times to ensure that the results are accurate.
- CC. There are at least two groups, one differing from the other by two or more variables.
- DD. There is one group for which the scientist controls all variables.
Answer
The correct answer is A: a controlled experiment includes at least two groups, one of which does not receive the experimental treatment, allowing for a comparison of effects. This method is essential for determining the relationship between variables. The control group serves as a baseline to measure the effect of the treatment applied to the experimental group.
Explanation
A controlled experiment is a type of scientific investigation that aims to determine the effect of a single variable while keeping others constant. The main components of a controlled experiment are: Two Groups: There are at least two groups involved in the experiment. One group is known as the experimental group, which receives the treatment or manipulation being tested. The other group is called the control group, which does not receive the experimental treatment. This group serves as a baseline to compare against the experimental group. Control Variable: In a controlled experiment, all other variables should be kept constant to ensure that any observed effect is due solely to the independent variable being tested. Independent and Dependent Variables: The independent variable is the one that is deliberately changed or manipulated. The dependent variable is what is measured or observed in response to changes in the independent variable. Repetition: Controlled experiments are often repeated multiple times to confirm the results and ensure reliability. In summary, the best answer to the question about what constitutes a controlled experiment would be option A: 'There are at least two groups, one of which does not receive the experimental treatment.' This configuration allows researchers to establish a cause-and-effect relationship between the independent variable and the dependent variable by comparing the outcomes between the experimental and control groups.