STATISTICS

• data


  Information collected for analysis
• variable


  A characteristic that can change or vary
• population


  The entire group of interest
• sample


  A subset of the population used for data collection
• mean


  The average of a set of numbers
• median


  The middle value in a sorted dataset
• variance


  It is the square of the standard deviation
• interquartile range


  The difference between the upper quartile (Q3) and lower quartile (Q1)
• outlier


  A data point that is significantly different from other data points
• histogram


  A graph that shows the distribution of data using bars
• box plot


  A dataset using quartiles and outliers
• scatter plot


  To show the relationship between two variables
• pie chart


  Parts of a whole as slices of a pie
• probability


  The chance of a specific event occurring
• hypothesis testing


  A method for determining whether a hypothesis about a population is supported by sample data
• correlation


  A statistical relationship between two variables
• regression


  A statistical method for predicting the value of one variable from another
• sampling bias


  A systematic error in the way a sample is selected that can lead to inaccurate results
• placebo effect


  A psychological effect that occurs when a person believes they are receiving a treatment, even if it is not real
• ungrouped data


  Data that has not been organized into groups
• grouped data


  Data that has been organized into groups or categories
• class interval


  The range of values in each group of data
• tally marks


  To represent frequencies
• stem and leaf plot


  A graphical representation of data that shows both the stem (leading digits) and leaf (trailing digits) of each value
• frequency polygon


  A line graph that connects the midpoints of the bars in a histogram
• cumulative frequency


  A distribution that shows the cumulative total of frequencies for each class interval
• parameter


  A numerical or descriptive measure that describes an entire population
• statistic


  A numerical or descriptive measure that describes a sample
• descriptive statistics


  Methods for summarizing and presenting data
• Inferential statistics


  Methods for drawing conclusions about a population based on sample data
• quantitative data


  Numerical data that can be measured
• qualitative data


  Categorical data that describes qualities or characteristics
• discrete variable


  A variable that can only take on specific, distinct values
• continuous variable


  A variable that can take on any value within a range
• nominal scale


  A scale that categorizes data into mutually exclusive categories
• ordinal scale


  A scale that categorizes data into ordered categories
• interval scale


  A scale that allows for the measurement of differences between values, but does not have a true zero point
• ratio scale


  A scale that allows for the measurement of differences between values and has a true zero point
• validity


  The extent to which a measurement tool accurately measures what it is intended to measure
• reliability


  The consistency of a measurement tool over time