Types of data and variables Flashcards
What is data?
Measurements of one or more variables made on a sample of individuals
What are the two types of data?
Categorical and numerical
What are the two types of categorical variables?
Nominal and ordinal
What is a categorical variable?
An attribute, something qualitative
What is nominal data?
A name, a membership to a group/category. There is no inherent order
What is ordinal data?
Categorical data that has an order to it, but no magnitude
What is a numerical variable?
Variables that are quantitative and have magnitude
What is continuous data?
The data can be any real number value within a range, including decimals
What is discrete data?
The data are indivisible numerical units that are counts. No decimals
What are two problems with distinguishing categorical from numerical data?
- Discrete values can get analyzed as continuous data if there’s a large number of possible values
- Categorical variables can sometimes be indexed by numbers (1 is presence of trait, 0 is absence)
What is interval data?
Type of numerical data measured along a continuum that has every interval at an equal distance from each other
What is ratio data?
Is a type of interval scale where zero is meaningless and absolute
What are the 4 levels of measurement from least to most sophisticated?
- Nominal
- Ordinal
- Interval
- Ratio
What is a response variable?
The thing that is responding to the other thing
What is an explanatory variable?
The thing that is influencing the other thing, the thing that is being manipulated
