Research methods controlling variables

Summary

In this video, the speaker explores how to control variables in experiments, specifically focusing on extraneous and confounding variables. Using an experiment on the effects of music on concentration as an example, key control strategies are discussed, including counterbalancing to address order effects, random allocation for participant variables, standardized procedures for situational variables, and double-blind designs to minimize investigator effects. The importance of these controls is emphasized to ensure valid and reliable experimental results, making it essential for researchers to consider these factors when designing their studies.

Takeaways

• 😀 Controlling variables is essential in experiments to ensure valid results.
• 🎶 Extraneous variables may affect the dependent variable and must be controlled.
• 🧩 Confounding variables are known to impact the dependent variable and should be identified and managed.
• 🎼 The example experiment examines how rock and classical music affects concentration measured by a word search task.
• 🔄 Order effects can lead to improved or decreased performance based on the sequence of conditions participants experience.
• 🎲 Random allocation helps reduce systematic differences among participants in different groups.
• 👥 Matched pairs design can minimize participant variable impacts, but is not always suitable for repeated measures designs.
• 🕒 Situational variables, such as time of day and environmental distractions, must be standardized across all participants.
• 📜 Standardized procedures and instructions ensure consistency in the experimental process.
• 🔍 Double-blind design prevents both participants and researchers from knowing the study's aims, reducing bias in behavior.

Q & A

What are extraneous variables in an experiment?

Extraneous variables are factors that are not the main focus of the study but can influence the outcome of the experiment.

What distinguishes confounding variables from extraneous variables?

Confounding variables are specific extraneous variables that are known to affect the dependent variable, potentially skewing the results of the study.

Can you give an example of a concentration task used in the discussed experiment?

The concentration task used in the experiment is completing a word search.

What types of music were compared in the experiment?

The experiment compared the effects of rock music and classical music on concentration.

What are order effects and how can they be controlled?

Order effects refer to changes in performance due to the sequence in which conditions are presented. They can be controlled by counterbalancing or using an independent groups design.

How does random allocation help in controlling participant variables?

Random allocation ensures that participants are assigned to different groups randomly, which helps create varied and representative groups, reducing the likelihood of biased results due to participant characteristics.

What are situational variables, and why are they important?

Situational variables are external factors such as time of day or environmental noise that can affect participants' performance. Controlling these variables is important to ensure that any observed effects are due to the independent variable being tested.

What is the role of standardized procedures in an experiment?

Standardized procedures ensure that all participants experience the same conditions and instructions during the experiment, which helps reduce variability and increases reliability.

What is a double-blind design and why is it used?

A double-blind design is when neither the participants nor the experimenters know the aims of the study. It is used to minimize bias in behavior and data collection.

What are some participant variables that could affect the results of the concentration task?

Participant variables that could affect results include IQ, mood, personality traits, and prior experience with word searches.