types of extraneous variable and their control Flashcards
(18 cards)
What are participant variables?
Personal characteristics that individuals bring to an experiment which may influence their responses.
Examples include intelligence, memory, age, diet, sleep patterns, and cultural experiences.
How can participant variables be controlled in an experiment?
Through random sampling and random allocation to ensure a representative sample and uniform spread of participant characteristics.
Random sampling ensures that participants are representative of the population being studied.
What is within subjects design?
An experimental design where all participants perform under all conditions, making participant variables constant.
This design is more effective for controlling participant variables.
What is between subjects design?
An experimental design where different participants are assigned to different conditions, with random allocation to ensure uniform spread of participant characteristics.
This reduces the likelihood of differences between groups.
What are situational variables?
External factors associated with the experimental setting that could influence participant responses.
Examples include background noise, time of day, temperature, and presence of others.
What are order effects?
Effects arising from the sequence in which experimental tasks are presented, influencing performance on the dependent variable.
They can be practice effects or carryover effects.
What are practice effects?
Improvements or impairments in performance due to prior experience with the tasks.
Familiarity can lead to better performance while fatigue can lead to worse performance.
What are carryover effects?
The influence from doing a previous task on the performance of the next task.
Examples include lingering emotions or substances affecting later trials.
How can situational variables be controlled?
By holding them constant during the experiment and ensuring all participants are tested in the same way.
This helps conclude that the independent variable was manipulated effectively.
What is counterbalancing?
A method of controlling order effects by systematically changing the sequence of tasks for participants.
It reduces or avoids unwanted effects on performance.
What are demand characteristics?
Cues in an experiment that may influence or bias a participant’s response.
These cues can suggest the expected response, leading to non-natural responses.
How can demand characteristics be controlled?
Through deception, blind procedures, and appropriate experimental design.
Deception involves misleading participants about the purpose of the experiment.
What is the placebo effect?
A change in participants’ behavior due to the belief that they are receiving treatment, rather than the actual effects of the independent variable.
To minimize this effect, a control group can be given a placebo.
What is experimenter effect?
Any influence the experimenter may have on the results of their investigation.
This can occur through interaction with participants or unintentional errors.
What is experimenter expectancy?
Cues provided by the experimenter about expected participant responses, which can lead to a self-fulfilling prophecy.
This includes unintentional biases in data treatment.
What is a double-blind procedure?
A method where both participants and experimenters are unaware of the experimental conditions.
This helps prevent experimenter cues and control participant expectations.
What is a triple-blind procedure?
A method where participants, experimenters, and research assistants are all unaware of the experimental conditions.
Digital technology can help maintain this blindness.
What is the aim of controlling participant variables?
To ensure that participants in different experimental conditions are as similar as possible in personal characteristics that may influence results.
