histogram - ANSWER-values or grouped into equal width intervals, summarizes
quantitive data, does not show exact values, useful for large data sets
time series plot - ANSWER-show data that is collected over time, time on x-axis,
variable of interest on y-axis, trend are more easy to identify
side-by-side box plot - ANSWER-graph of distribution between one categorical and one
quantitive variable
z-score - ANSWER-a measure of how many standard deviations you are away from the
mean
response variable - ANSWER-a variable that measures an outcome of a study, y-axis
explanatory variable - ANSWER-a variable that we think explains or causes changes in
the response variable, x-axis
lurking variable - ANSWER-a variable that is not among the explanatory or response
variables in a study but that may influence the response variable
random sampling - ANSWER-a method of poll selection that gives each person in a
group the same chance of being selected
categorical variables - ANSWER-a variable that names categories (descriptive words or
phrases)
dichotomous variable - ANSWER-a nominal variable that consists of two categories
(gender)
ordinal variable - ANSWER-a qualitative variable that incorporates an ordered position,
or ranking (freshmen, sophomore, junior, senior)
frequency - ANSWER-the number of observations in each category
percent - ANSWER-A ratio that compares a number to 100
proportion - ANSWER-the number of observations in each category divided by the total
number of observations
, modal category - ANSWER-the category with the highest frequency
quantitative variables - ANSWER-a variable that takes on numeric values
continuous variable - ANSWER-a quantitative variable that has an infinite number of
possible values that are not countable (9.63,9.75,9.79...)
discrete variable - ANSWER-a quantitative variable that has either a finite number of
possible values or a countable number of possible values (0,1,2,3...)
unimodal distribution - ANSWER-one peak
bimodal distribution - ANSWER-two peaks, not symmetric, not bell-shaped
left-skewed - ANSWER-mean < median
right-skewed - ANSWER-mean > median
symmetric distribution - ANSWER-the right and left sides of the histogram are
approximately mirror images of each other
uniform distribution - ANSWER-all values seem approximately equal
measures of central tendency - ANSWER-mean, median, mode
measures of spread - ANSWER-standard deviation, variance, range, iqr
mean - ANSWER-average, more resistance to outliers
median - ANSWER-the middle value of the ordered data, less resistance to outliers
mode - ANSWER-the value of the data that occurs the most frequently
standard deviation - ANSWER-represents a type of average distance of an observation
from the mean, larger=greater the variability
anecdotal evidence - ANSWER-data collected in a haphazard fashion
descriptive statistics - ANSWER-used to summarize the collected data through numbers
such as averages and percentages; measures of central tendency and measures of
variability