Unit 1: Exploring One-Variable Data Flashcards
Statistics
The science of reasoning from data (Dealing with Data)
Population
The entire group of people/things that you want to investigate.
Sample
Smaller portion of the population that you want to gather information about
Data
Actual values of the variables you find from sampling (Ex. the number of people who like certain sports the best)
Parameter
Data about a population (numerical characteristic)
Statistic
Data about a sample (numerical characteristic)
Variable
Element, feature, or factor that’s liable to vary or change
Convenience Sampling
A type of sampling that is NOT random and involves using a population that is READILY AVAILABLE
Quota Sampling
Using a sample that is selected to match the population with respect to some specific characteristic(s)
Cluster Sampling
Dividing the population into groups, then randomly selecting some of the groups
Systematic Sampling
Randomly selecting a starting point in a list of names and taking every nth piece of data from a listing of the population (a special subset of cluster samples)
Stratified Sampling
Dividing the population into groups, and then taking your sample from a proportionate number from each group
Observational Units
The person or thing to which the number or category is assigned
Datum
One piece of data
Variability
The phenomenon of a variable taking on different values or categories from observational unit to observational unit
Quantitative Variable
Measures a numerical characteristic such as height
Categorical Variable
Records a group designation such as gender
Binary Variables
Categorical variables with only two possible categories, for example, male and female
Bar Graph
Displays the distribution of a categorical variable
Distribution
The distribution of a variable refers to its pattern of variation. With a categorical variable, distribution means the variable’s possible categories and the proportion of responses in each.
Statistical Tendency
Refers to observational units in one group being more likely to a certain category or to have higher values than those in another group
Consistency
Refers to how variable, or how spread out, the values in a dataset are for a quantitative variable