Stats Flashcards
Qualitative vs quantitative data
quantitative = numerical data
qualitative = descrittive and conceptual e.g. interviews
Interval vs categorical
interval = continuous and qualitative e.g. height, blood pressure
categorical = discrete and qualitative
- ordinal - categories have rank order e.g. pain scale
- nominal - categories have no direct relation e.g. blood group
Parametric vs non-parametric
parametric = normal (bell shaped) distribution
non-parametric = all others
averages
central tendency of data
mode = most common value (useful for nominal)
median = numbers in ascending order, middle one (e.g. ordinal categorical - pain scale)
mean = sum of all data divided by number of values
normal distrubution - all the same
non-parametric may be skewed - positive mode, then median then mean
negative skew - mean then median then mode
Measurement of data spread
parametric - standard deviation. square root of sum of x-mean2/x-1
1 SD = 68% of values 2 SD = 96% of values 3 SD = 99.7%
non-parametric
- range / IQ range