information collected from whole (finite) population
7
New cards
Define Sample Survey
Information collected from a subset of the \n population
\ \*\*\*Often use the approach to sampling (and data collection) to distinguish between options...
8
New cards
Why do we want to use Sample Statistics?
to make inferences back about Population Parameters allowing for RANDOMNESS
9
New cards
How do you describe the population
by measuring relationships between variables at a point-in-time (correlations)
10
New cards
What matters most in samples and why?
RANDOM SELECTION! without it, we get biased
11
New cards
What are the variables when it’s a design for an experiment
Treatment variable and outcome variable
12
New cards
What are the \*\*other\*\* variables when it’s a design for an experiment and define it
__**EXPLANATORY VARIABLES**__
attributes we can measure that explain variation in the Outcome
e.g: The Treatment variable is just a ‘special case’ of an \n explanatory variable
\ \ __**CONFOUNDING VARIABLES**__
attributes we cannot measure that explain variation in the Outcome
e.g: With COVID-19 this might be attitudes to social distancing, approach to hygiene and isolation, or your job situation
\
13
New cards
What are cons in observational studies (rather than experiments)
* Can have SEVERE BIAS due to background effects * Correlations are not Causation
14
New cards
What are observational studies useful for?
* guiding the development of hypotheses for later experiments * We look for evidence of a response in a group getting the treatment BEFORE implementing a large expensive double-blind randomised controlled experiment
\ * Observational studies are useful for reinforcing the results of double-blind randomised controlled experiments
15
New cards
Define Single-Blind Trials
the participant does not know if they are \n Treatment or Control
16
New cards
Define Double-Blind Trials
neither the administrator of the experiment or the participant knows if they are Treatment or Control