3.5 Introduction to Experimental Design

• Experimental design is a structured approach to conducting experiments, involving the manipulation of independent variables to observe their effects on dependent variables.
• In observational studies, researchers have a high degree of control over variables.

  False
• Control in experimental design ensures the independent variable is the primary factor affecting the dependent variable.


  True
• Match the key component of experimental design with its purpose:

  Control ↔️ Minimizing extraneous variables

  Randomization ↔️ Reduces bias and improves validity

  Replication ↔️ Increases reliability and generalizability
• What type of study can suggest correlation but not causation?

  Observational study
• What does the treatment group receive in an experiment?

  Experimental intervention
• Match the features with the type of study:

  Researchers observe without intervening ↔️ Observational studies

  Researchers actively manipulate variables ↔️ Experiments
• What type of study is better for generating hypotheses?

  Observational studies
• What is an example of replication in experimental design?

  Repeating the experiment
• Order the steps to ensure a well-designed experiment

  1️⃣ Control extraneous variables

  2️⃣ Randomly assign subjects

  3️⃣ Replicate the experiment
• Which type of study involves deliberately manipulating independent variables?

  Experiments
• What is the primary purpose of randomization in experimental design?

  Reduce bias
• Experiments can be classified as either randomized or non-randomized based on how subjects are assigned to groups.
• Randomized experiments are considered the "gold standard" in experimental design because they provide the most robust evidence for establishing causation.

  True
• Match the type of study with its ability to establish causation:

  Experimental Design ↔️ Can establish causation

  Observational Studies ↔️ Suggests correlation only
• Order the benefits of replication in experimental design:

  1️⃣ Increases Reliability

  2️⃣ Enhances Generalizability

  3️⃣ Reduces Random Error

  4️⃣ Confirms Causation
• Why do vulnerable populations require extra precautions in research?

  Protect their well-being
• The key components of experimental design are control, randomization, and replication.


  True
• What type of study can establish causation?

  Experimental design
• What is the purpose of randomization in experimental design?

  Reduces bias
• Experimental design differs from observational studies, where researchers observe subjects without manipulation.
• Control in experimental design ensures the independent variable is the primary factor affecting the dependent variable.
• Observational studies have limited control over variables, while experiments have a high degree of control.
• Experiments have limited control over variables compared to observational studies

  False
• Control, randomization, and replication are key components of experimental design


  True
• Experimental design establishes causation
• What is the purpose of a control group in an experiment?

  Provides a baseline
• Observational studies actively manipulate independent variables

  False
• Random assignment ensures that any observed differences between groups are due to the independent variable, not confounding factors.

  True
• Match the type of experiment with its key feature:

  Randomized Experiment ↔️ Subjects are randomly assigned to groups

  Non-Randomized Experiment ↔️ Subjects are not randomly assigned
• What is a confounding variable in experimental design?

  Distorts true causation
• What is the primary purpose of replication in experimental design?

  Increase reliability
• What is informed consent in ethical research design?

  Voluntary agreement to participate
• Ethical concerns can impact experimental design by requiring additional controls.
• Experimental design differs from observational studies, where researchers observe subjects without manipulation.
• The essential components of a well-designed experiment are control, randomization, and replication.
• Replication in experimental design involves repeating the experiment with different samples or conditions.
• Observational studies involve actively manipulating independent variables.

  False
• The control group in an experiment receives the experimental treatment.

  False
• What are the two main types of research studies being compared in this material?

  Observational studies and experiments