1.1.4 Evaluation

• What is the primary goal of a well-designed experiment?

  Reliable and meaningful results
• What is the independent variable in an experiment?

  The variable manipulated
• Factors that are kept constant in an experiment are called controls
• Why is randomization important in experimental design?

  To minimize bias
• Sampling error occurs when the sample differs from the larger population.


  True
• Unconscious influence of the researcher's expectations on observations is called observer bias.
• Validity refers to the consistency and reproducibility of experimental results.

  False
• What is an example of an experiment with high validity but low reliability?

  Accurate plant height, variable trials
• Reliability refers to the consistency and reproducibility of the results
• Why is it important to assess both validity and reliability in an experiment?

  Determine data quality
• Randomization in experimental design helps ensure reliability.


  True
• Evaluating experimental results involves considering both validity and reliability
• Replication in experimental design helps ensure data reliability.

  True
• Evaluating whether results are consistent across multiple trials assesses their reliability
• Match the component of a well-designed experiment with its description:

  Hypothesis ↔️ A testable prediction

  Independent variable ↔️ Variable manipulated by researcher

  Dependent variable ↔️ Variable measured in response
• The independent variable is the variable measured in response to experimental changes.

  False
• Randomization in experimental design minimizes potential bias
• Sampling error occurs when the sample differs from the larger population being studied.

  True
• Minimizing sources of error is crucial to ensure the reliability and validity
• What is the term for inaccuracies or imprecision in the measuring instrument or technique?

  Measurement error
• What type of error occurs when a researcher's expectations unconsciously influence observations?

  Observer bias
• Match the source of error with its description:

  Measurement error ↔️ Inaccuracies in the measuring instrument

  Sampling error ↔️ Differences between sample and population

  Observer bias ↔️ Unconscious influence of expectations

  Experimental error ↔️ Uncontrolled factors affecting dependent variable
• A reliable experiment produces similar results when repeated under the same conditions.


  True
• What type of error can undermine the validity of experimental results?

  Observer bias
• What should a well-justified conclusion consider in experimental design?

  Potential sources of error
• What should researchers evaluate to determine if results are consistent across multiple trials?

  Reliability
• A hypothesis is a testable prediction about the relationship between variables
• The dependent variable is observed in response to changes in the independent variable.


  True
• Arrange the following steps in the design of a well-designed experiment:

  1️⃣ Formulate a hypothesis

  2️⃣ Identify independent and dependent variables

  3️⃣ Design controls

  4️⃣ Perform replicates

  5️⃣ Randomize experimental conditions
• One key source of error in data collection is measurement error.
• Match the source of error with its description:

  Measurement error ↔️ Inaccuracies in measuring instrument

  Sampling error ↔️ Differences between sample and population

  Observer bias ↔️ Researcher's expectations influence results
• What two factors are crucial for ensuring the quality of experimental results?

  Reliability and validity
• Experimental design factors like randomization and replication help ensure reliability
• What does validity refer to in experimental design?

  Measuring what intended
• An experiment testing fertilizer effects has high validity if it accurately measures plant height.


  True
• Sources of error, such as observer bias, can undermine the validity
• What is an example of an experiment with high validity but low reliability?

  Fertilizer testing
• What is a potential source of error that can undermine the validity of experimental results?

  Observer bias
• What should a well-justified conclusion consider in experimental results?

  Potential sources of error
• What does the term "justification" refer to in evaluating conclusions from experimental data?

  Reasonableness of conclusion