Lecture 5 Flashcards
What are the basic things you need to consider in an experiment?
-experimental vs control condition
-operational definition
-Independent vs. dependent variables
-single vs double blind experiment
- experimenter bias
what does longitudinal research use? Why is this problematic?
Because it uses correlations, it is still susceptible to confounds
how do we get around confounds?
we can manipulate the variable we’re interested in.
What are confounds?
3rd variables
what are 2 confounding variables for Violence and Video games?
Child’s temperament and lack of parental supervision
How many variables can influence a relationship?
potentially an infinite number of 3rd variables that could influence a relationship
In an experiment testing video games and violence, If the measure of violent behaviour is similar between 50 participants who play a violent video game and 50 participants play a non-violent video game what kind of effect is this?
A null effect
How do we use variables in experimentation?
we manipulate one variable and observe its effects on another variable.
What is the independent variable?
The variable you manipulate to see its effects on the outcome variable
What is the dependent variable?
The outcome variable- the variable that is measured or is of interest in the study (ex: violent behaviour)
What is the experimental group?
The group that recieves the intervention
What is the control group?
The group that does not receive the intervention
what process should you use to divide your sample into conditions?
Randomization
Why do we randomly assign participants to conditions?
That way every participant has an equal opportunity to be assigned to the control or experimental condition
In an experiment, what do you need to do after randomization and why?
You need to go through and make sure the randomization worked because it is still statistically possible to get similar people in each group.
What are the three steps to doing randomization effectively?
Start with a survey, do random assignment, check to see it worked
What is it called when you define your dependent variable? Why is it important?
It is called your operational definition. It is important because it dictates how you measure it and what conclusions you can draw from it. We must be CONSISTENT with our definition.
What is a quasi-experimental design?
When we perform an experiment on 2 naturally occurring groups. (Think back to shaved head vs luscious hair Simon likability experiment)
what is the problem with Quasi-experimental design?
they are useful but limit claims we can make about causality?
What is an example of a quasi-experimental design?
Giving students in totem warm milk after dinner and giving students at orchard coffee and seeing who sleeps better.
What does blind mean in science?
unaware
What is the problem with single blind experiments?
Experimenters interpretation of behaviour could be influenced by experimenter beliefs
what is a double blind experiment?
when both the researcher (experimenter) and participants are unaware of the condition/hypothesis of the study.
What happened in the study of Rosenthal and Fode? (Fast mouse slow mouse)
both mice were actually genetically the same but data collected reflected experimenter’s expectations.
What is a sample?
a subset of the population
what is an example of a bias subset?
Most studies are done on undergraduate students (typically more liberal, more educated and less diverse)
What are people looking for in a sample?
participants who are representative of the population
What do random samples allow?
more confidence in generalizing the effects from the sample to the population as a whole
What did Sir Francis Galton do?
-measured intelligence using reaction time (e.g how quickly someone could classify a sound)
-Did the first set of studies into intelligence (developed psychometrics, created correlation coefficient math)
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What factor do we look at when thinking about vallidity?
does our instrument actually measure what we want it to measure?
What factor do we look at when thinking about ecological validity?
Interested in behaviour as it occurs in its natural element
What factor do we think about when considering reliability?
Does our test return consistent results (i.e Big 5 personality test vs Myers Briggs Personality test)
What was the problem with the Tuskegee syphilis study?
did not tell the patients that they had syphilis and did not offer to cure them when cure was discovered despite offering ‘free medical care’. Syphilis spread throughout community.
what year was the national research act?
1974
What year was the Tuskegee study stopped?
1972
What are the 4 rules of ethics concerned with experimentation?
- no harm should come to participants
-respect for human dignity and safety
-Participants must give informed consent
-must be free to withdraw consent at any point without penalty
What is informed consent?
participants give consent only after being informed on what the study is about and the associated risks
Is deception sometimes necessary and allowed in experiments?
Yes but it must be well motivated
How does the scientific community gain understanding of the phenomena around us
through empiricism
what is the scientific method?
A set of procedures that use empirical data
What do correlations tell us?
They tell us about the direction and strength of 2 variables
Think: Can you explain the learning outcomes? (Read the back and see how well you can explain them)
What are the basic parts of an experiment?
- Experimental vs. Control condition
- Operational definition
- Independent vs. dependent variables
-Compare and contrast single- and double-blind experiments
-What is experimenter bias?
What role does randomization play in sampling and in experimental conditions Define and identify validity and reliability in research.
