Statistical Inferences Flashcards
if the data is not normal or has outliers, how is central tendency calculated?
median is calculated as an indicator of central tendency
mean and median are used for _______
mode is used for ______
mean/median = interval / ratio data
mode = categorical data, nominal/ordinal
what is used to measure dispersion if data is skewed
IQR
difference between lower and upper quartile comprises middle 50% of data
what is used to measure dispersion if data is not skewed
SD
range
P value means
0.05 or less
indicative of the fact that the difference between 2 groups is not by chance and that there is a significant difference
null hypothesis definiton
no difference between variables
alternative hypothesis definiton
there is a difference between results of variables
if the P value is <0.05 we accept the
alternative hypothesis
what is alpha error
probability of concluding that there is a difference when there actually is not
accepting alternative hypothesis when we should not
what is beta error
concluding that there is no difference between treatment groups when there was
accepting null hypothesis when we shouldnt have
how is beta error denoted
between 0.15-.2
beta error is used to describe
power of the study
defined by 1 - B error
how is type 2 error made
small sample size
– imprecise estimates of differences in mean of two treatment groups
