Experimental design is a plan for conducting experiments to test hypotheses, ensuring that meaningful and valid results can be obtained.
What are independent and dependent variables in an experiment?
Independent variables are those manipulated to observe their effect, while dependent variables are those that are measured in response to changes in the independent variables.
Why is random assignment important in experimental design?
Random assignment helps ensure that each participant has an equal chance of being placed in any group, reducing bias and improving the reliability of results.
What is a control group in an experiment?
A control group is the group in an experimental study that does not receive the experimental treatment, used as a baseline to compare with the experimental group.
What is a double-blind study, and why is it used?
A double-blind study is one in which neither the participants nor the researchers know who is receiving the treatment, reducing bias in the results.
What is random error, and how does it differ from systematic error?
Random errors occur unpredictably and affect measurement precision, while systematic errors are consistent and affect accuracy.
What is the purpose of replication in experimental design?
Replication confirms the reliability of experimental results by repeating the study under the same conditions.
Describe a factorial design in experiments.
A factorial design involves testing two or more independent variables across various combinations to study their effect simultaneously.
What is the main limitation of case studies in experimental design?
Case studies often lack generalizability, as they focus on the detailed examination of a single subject or event.
Define internal validity in the context of experimental research.
Internal validity refers to the extent to which an experiment establishes a trustworthy cause-and-effect relationship between variables.
What is the Hawthorne Effect?
The Hawthorne Effect is where subjects modify their behavior because they are aware they are being observed.
Explain the difference between correlation and causation in experiments.
Correlation indicates a relationship between two variables, while causation shows that one variable directly affects the other.
What is an experimental bias, and how can it be minimized?
Experimental bias is a distortion of results due to unintended influences by the researcher, which can be minimized through blind setups and standardized procedures.
What role do hypotheses play in experimental design?
Hypotheses provide a statement or prediction that guides the experiment, serving as a foundation for testing and analysis.
How does a hypothesis differ from a theory in experimental science?
A hypothesis is a testable prediction, while a theory is a well-substantiated explanation based on a body of evidence.