A table in which data values are divided into either a "leaf" or a "stem." In a stem and leaf plot, the stem values appear on the vertical axis and the leaf values are listed on the horizontal axis.
A form of nonprobability sample using respondents who are convenient or readily accessible to the researcherfor example, employees, friends, or relatives
Anything in the survey design that influences the responses from the sample
Range of the middle 50 of the values; Q3-Q1 75th percentile - 25th percentile