Data

**Key Concepts**

 * **Context: The context ideally tells WHO was measured, WHAT was measured, HOW the data were collected, WHERE the data were collected, and WHEN and WHY the study was performed.**


 * **Data: Systemically recorded information, whether numbers or labels, together with its context.**


 * **Data table: An arrangement of data in which each row represents a case and each column represents a variable.**


 * **Case: A case is an individual about whom or which we have data.**


 * **Variable: A variable holds information about the same characteristics for many cases.**


 * **Categorical variable (qualitative): A variable that names categories (whether with words or numbers)**


 * **Quantitative variable: A variable in which the numbers act as numerical values and they will always have units.**


 * **Units: A quantity or amount adopted as a standard of measurement, such as dollars, hours, or games.**