Ch. 9 - Conducting Studies Flashcards
Straightforward manipulations
-Researchers can manipulate a variable simply by presenting material to the participants
Staged manipulations
- Sometimes it is necessary to create a series of events that occur during the experiment to manipulate the independent variable successfully
- Can be elaborate situations involving actors or a cover story (ie. deception is often involved)
Manipulation strength
- In general, try to make the manipulation as strong as possible
- Essentially, this means making the levels of the independent variable maximally different, while keeping everything else between the 2 groups the same
Manipulation check
- Researchers sometimes use a manipulation check to attempt to directly measure whether the independent variable manipulation induced the intended psychological state among participants
- Provide evidence for the construct validity of the manipulation
Self-report measure
-Can be used to measure explicit attitudes, liking for someone, judgements about someone’s personality characteristics, intended behaviours, emotional states, attributions about why someone performed well or poorly on a task, confidence in one’s judgements, and many other aspects of human thought and behaviour
Behavioural measure
-Is a direct observations of behaviours
Physiological measures
- A recording of a response of the body
- The galvanic skin response (GSR) is a measure of general emotional arousal and anxiety. It measures the electrical conductance of the skin, which changes when sweating occurs
- The electromyogram (EMG) measures muscle tnesion
- The electrocardiogram (ECG) measures heartbeat regularity and rate
- Both EMG and ECG are used as measures of tension and stress
- The electroencephalogram (EEG) is a measure of electrical activity of brain cells. It can be used to record general brain arousal as a response to different situations, activity in different parts of the brain as learning occurs, or brain activity during different stages of sleep
- MRI captures images of brain structures
- fMRI scans the brain while a participant performs a physical or cognitive task
Ceiling effect
-The independent variable might “appear” to have no effect on the dependent measure only because participants quickly reach the maximum performance level (ie. the task is TOO EASY)
Floor effect
-When a task is so difficult that hardly anyone can perform well
Demand characteristic
-Is any feature of a study that might inform participants of its purpose and consequently affect their behaviour
-To control for demand characteristics:
-Researchers can use deception, ie. using a cover story, leading participants to think the experiment is studying one thing when actually it is studying something else
Can also disguise the dependent measure by using filler items on a questionnaire
- To assess if demand characteristics are a problem:
- Asking participants about their perceptions of the purpose of the research
Waitlist control condition
-Participants in the control conditions may be given the treatment after the study is completed
Single-blind procedure
-The participants are unaware of which condition they are in (ex. whether a placebo or the actual drug is being administered)
Double-blind procedure
-Neither the participant nor the experimenter knows the participant’s condition
Pilot study
- When procedures are particularly elaborate or costly, or when there will be only a single opportunity to collect data, researchers sometimes choose to conduct a PILOT STUDY in which the researcher does a “trial run” with a small number of participants drawn from the same population as the sample he or she ultimately hopes to test
- Pilot study details must be included in the ethics application
