Stats Flashcards
Sample
a subset or portion of the full population (representatives)
When is a sample useful
When studying the complete population is not feasible
What is commonly utilized to draw samples
random processes
study measurments
- measurements are collected on desired variables
- comparisons are made (statistical analyses)
- Inferences will be made about the sample-derived measurements and their comparisons
(inferences will also be made to the full population of similar subjects (generalizability))
Null hypothesis
perspective which states there will be no (true) difference between groups
-most conservative and commonly utilized
- Various statistical-perspectives can be taken by the researcher
- superiority
- Noninferiority
- Equivalency
Alternative hypothesis
Perspective which states there will be a (true) difference between the groups being compared
what are the 2 key attributes of data measurements (variables)
- Magnitude (or Dimensionality)
- Consistency of scale (or Fixed interval)
- equal, measurable spacing between units
Study population
the final group of individuals selected for a study
What are the 3 key levels and attributes of measurements
- Nominal
- Ordinal
- Interval/Ratio
Explain Nominal data
- Dichotomous/Binary; non-ranked Named categories
- No magnitude/No consistency of scale / No Rational Zero
- Nominal variables are simply labeled variables without quantitative characteristics
_______ variables are simply labeled variables without quantitative characteristics
Nominal
Explain Ordinal Data
- Ranked categories; non-equal distance
- Yes Magnitude/no consistency of scale/ no Rational zero
Interval/Ratio Data
- order and magnitude and equal intervals-of-scale (units)
- Yes magnitude/ Yes consistency of scale/ no or yes rational zero (no-interval; yes-ratio)
Ex. - Number of living sibling and personal age (in years)
after data is collected, we can appropriately go _________ specificity/detail of data measurements (levels), but never go ____
down, up
What are the two discrete data types
nominal and ordinal
What kind of data is continuous
interval
Mean/Median/mode are only useful for _____ data
continuous
Difference in each individual measurement value and the groups’ mean
Variance
Square root of variance value (restores units of mean)
Standard Deviation
Stat tests useful for normally-distributed data are called ________ tests
Parametric
Asymmetrical distribution with one “tail” longer than another
Positively skewed
A distribution is skewed anytime the _____ differs form the _____
median differs from the mean
When mean is _____ than median it is _____ skew
positive skew
Asymmetrical distribution with one “tail” longer than another
Negatively skewed