Biostatistics

What variable has more than two categories for example whether someone is an omnivore, vegetarian, or vegan?

nominal variable

What variable is the same as a nominal variable but the categories have a logical order such as disease progression: stable disease, improvement, recovery?

ordinal variable

What variable has only two categories such as dead or alive?

binary variable

What numeric measurement has distinct, countable values that cannot be broken down into fractions?

discrete

What numeric measurement has measurable values from within a range including fractions and decimals?

continuous

What are the two divisions of continuous?

interval variable and ratio variable

What variable has equal intervals on the variable represent equal differences in the property being measured, for example, the difference between 6 and 8 is equivalent to the difference between 13 and 15?

interval variable

What variable is the same as interval variable but the ratios of the scores means something, there is a meaningful zero, no negative numbers, and an example is a score of 16 on an anxiety scale means that the person is in reality twice as anxious as someone scoring 8?

ratio variable

What is bell shaped and symmetrical?

normal distribution

What is the symmetry of the distribution?

skew

What is the heaviness of the tails?

kurtosis

What is having two/several modes?

bimodal, multimodal

What is the sum of scores divided by the number of scores and is a central tendency?

Mean

What central tendency is the most frequent score?

Mode

What central tendency is the middle score when scores are ordered and when the data contain an even number of scores, you take the average of the middle two values?

Median

What is the dispersion when the smallest score is subtracted from the largest?

Range

What is when the max and min are mathematically restricted and if data cluster at a boundary such as function and pain assessments, incidence of rare disease, and test scores?

Bounded data

What measure of dispersion are the three values that split the sorted data into four equal parts then the upper quartile minus the lower quartile?

Quartiles, Interquartile Range

What is the measure of the spread of scores by looking at how different each score is from the center of a distribution or the mean?

deviance

What is a measure of total dispersion from the mean, its size is dependent on the number of scores in the data?

sum of squared errors

What is the average dispersion?

Variance

What is the square root of variance?

standard deviation

What do the sum of squares, variance, and standard deviation represent?

The ‘fit’ of the mean to the data, the variability in the data, how well the mean represents the observed data, error

What has equal intervals represent equal differences in the property being measured?

Interval variable

What has equal intervals represent equal differences plus the ratios of scores can be interpreted, and there is a meaningful zero and no negative numbers?

ratio variable

Which descriptive measures may not apply well to all data types including discrete, interval, and ratio?

mean, median