Week 5 Flashcards
summary statistics
summarise and provide information about sample data; measures of location (central tendency), measures of spread, graphs/charts
The precision of the estimate will depend on
sample size
t test general assumptions
data approximately normal
participants randomly selected
participants within the sample independent
steps in hypothesis testing
state hypotheses state assumptions calculations interpretations conclusions
larger data
histogram
small data
boxplot
equality of variance
levene’s test (p value = 0.05, unequal variances)
(larger SD)^2/(smaller SD)^2
>/= 2, assume unequal variance
type I error
reject the null hypothesis when it is true
false positive
type II error
retain the null hypothesis when it is false
false negative
most serious errror
type I
power of a hypothesis test
not committing a type 2 error
rejection of the null hypothesis when the null is false
affected by sample size, significance level and true value of parameter
margin of error and CI
Value of ‘multiplier’ increases as the CL increases and hence the margin of error increases
If the margin of error increases, CI becomes wider
CI includes 0
not significant
CI does not include 0
significant
open RCT
Everybody involved knows which intervention is given to each patient
