Week 4 Flashcards
correlation (2)
- there is a relationship between two or more variables
- relationship does not necessarily imply cause and effect
What does it mean when two variables are correlated?
- as one variable changes, so does the other
correlation coefficient (3)
- number from -1 to +1 that indicates strength and direction of relationship between variables
- represented by letter r
- a statistic that is calculated to measure correlation
What does the number portion of correlation coefficient indicate?
- strength of the relationship
What does it mean when the correlation coefficient is closer to one (positive or negative)? (2)
- the more strongly related the variables
- the more predictable changes in one variable will be as the other variable changes
What does it mean when the correlation coefficient is closer to zero? (2)
- the weaker the relationship
- the less predictable the relationships between the variables become
What does a correlation coefficient value of zero indicate?
- no correlation
What does the sign (positive or negative) of the correlation coefficient indicate?
- direction of the relationship
What does a positive correlation coefficient indicate? (2)
- variables move in the same direction
- when one variable increases, the other variable increases
What does a negative correlation indicate? (2)
- variables move in opposite direction
- decrease in one variable is associated with a increase in the other variable
What are examples of positive correlation? (2)
- relationship between an individual’s height and weight
- relationship between person’s age and number of wrinkles
What is an example of a negative correlation?
- relationship between one’s tiredness during the day and the number of hours they slept the previous night
Why is correlational research useful?
- allows us to discover strength and direction of relationships that exist between 2 variables
Why is correlation limited?
- establishing existence of a relationship tells us little about cause and effect (causation)
confounding variable (2)
- unanticipated outside factor that affects both variables of interest
- often giving the false impression that changes in one variable causes changes in the other variables, when the outside factor causes changes in both variables
cause and effect relationship
- changes in one variable cause the changes in the other variable; can be determined only through an experimental research design
Where are claims of causation as a function of correlations common?
- advertisements and news stories
illusory/false correlations
- occur when people believe that relationships exist between two things when no such relationship exists
Why are we so apt to believe in illusory correlations? (3)
- often we read or hear about them and simply accept information as valid
- we may have a hunch and look for evidence to support the hunch, ignoring evidence that would tell us our hunch is false
- what we believe based on information that comes easily to mind, even if severely limited
confirmation bias
- highlighting evidence that supports our belief and ignoring contradictory evidence
What are the drawbacks of illusory correlations? (2)
- certain behaviours inaccurately attributed to certain groups
- involved in formation of prejudicial attitudes that can lead to discriminatory behaviour
What is the only way to establish a cause-and-effect relationship between 2 variables?
- conduct a scientific experiment
How is a hypothesis formulated?
- formulated through direct observation of the real world or after careful review of previous research
What two groups does the most basic experimental design involve?
- experimental group and control group
experimental group
- receives experimental manipulation, the treatment or variable being tested
control group
- does not receive experimental manipulation
operational definition (2)
- description of how we will measure our variables
- important in allowing others to understand exactly how and what a researcher measures in a particular experiment
Why are operational definitions important to an experiment?
- aids peoples’ ability to interpret our data as well as their capacity to repeat our experiment
experimenter bias
- possibility that researcher’s expectations might skew the results of the study as they observe behaviour
single-blind study
- one of the groups (participants) are unaware as to which group they are in (experiment or control) while the researcher who developed experiment knows which participants are in each group
double-blind study (3)
- both researchers and participants are blind to group assignments
- control for both experimenter and participant expectations
- method for avoiding confounded variable
placebo effect
- people’s expectations or beliefs influence or determine their experience in a given situation; expecting something to happen can actually make it happen
independent variable (2)
- manipulated or controlled by experimenter
- only important difference between experimental and control groups
dependent variable
- what researcher measures to see how much effect the independent variable had
What do we expect when looking and the independent and dependent variable?
- we expect the dependent variable to change as a function of the independent variable
participants
- subjects/individuals involved in psychological research
Which group is used often for psychological research?
- college students
What characteristics define college students relative to the general population? (4)
- younger
- more educated
- more liberal
- less diverse
Why can just using college students for psychological research be problematic?
- relying on such a limited pool of research participants can be problematic because it is difficult to generalize findings to larger population
random sample
subset of larger population where every member of the populations has an equal change of being selected