What is a psychological construct?
Hypothetical factor, explanation of phenomena (behaviour) e.g. hunger, wellbeing, happiness, body image, all of these existence is inferred
What does empirical mean?
Verified by observation rather than theory or pure logic, all knowledge is derived from senses.
4 different uses of quantitative data-
Measure things, to see if things vary with other things e.g does rising in teen depression correlate with something like social media use , to compare things e.g. wellbeing before and after using app, evaluate if something works
What is an operational definition?
how a construct is defined or measured in a particular study so its always directly measured
what is a categorical variable?
A type of variable that represents distinct categories or groups, can be nominal (without specific order e.g. colours or fruit) or ordial (with defined order like rankings or levels of satisfaction)
what is a continuous variable?
a number which may have an infinite number of possible values
ratio- height in cm can’t be negative
interval- can be negative e.g. score on questionnaire
is observational research sufficient evidence for causality?
No
How can observational research support causality?
If association is strong, temporal relation is appropriate (a happens before b if b happens before a a cant cause b), variables are specific.
Is correlation enough to establish causality?
It’s necessary but not sufficient
Correlation and possible causality
depression= low self esteem
3 explanations
= correlation
>cause
depression> low self esteem
low self esteem> depression
or
these correlate and there’s a third variable causing both e.g. life events
proof vs disproof
cannot prove presence of something just disprove absence of something e.g all swans white no amount of white swans can prove this one black swan can disprove
What is a between groups or independent measures design?
Two or more groups of participants exposed to DIFFERENT treatment or condition
What is a within group or related measure design?
all participants exposed to ALL treatments or conditions
Benefits of within group experiments
doesn’t require large pool participants, can reduce errors associated with individual differences
Disadvantages of within group experiments
Taking part in one condition can impact performance or behaviour on other conditions, no participant blinding
What is participant blinding?
Prevent bias participants not know which research group they’re in
Between groups design benefit
Can be tested simultaneously, multiple variables
between groups design disadvantages
Complex require many participants, assignment bias, observer-expectancy bias and subject expectancy bias - common causes skewed results
3 criteria for causality
- X proceeds Y in time (temporal relationship)
- X and Y are associated (correlated)
- All other causes of Y are ruled out
What happens in an experiment?
Manipulate independent variable “x” and observe effect on an outcome measure the dependent variable “y” attempt to control all other variables other than independent variable
