Categorical Data:
- Nominal: Data that represents qualitative categories with no inherent order (e.g., gender, occupation, political affiliation).
- Ordinal: Data that represents qualitative categories with a defined order (e.g., Likert scale responses, education level).
Numerical Data:
Discrete Data:
- Count: Data that represents whole numbers and can only take on specific values (e.g., number of students in a class, number of clicks on a website).
- Discrete Ordinal: Data that represents discrete values with an inherent order (e.g., exam scores, grades).
Continuous Data:
- Interval: Data that represents values along a continuous scale with equal distances between intervals but lacks a true zero point (e.g., temperature in Celsius or Fahrenheit).
- Ratio: Data that represents values along a continuous scale with a true zero point, allowing for meaningful comparisons of ratios (e.g., height, weight, population size).
Other Data Types:
- Boolean: Data that takes on two possible values, usually "true" or "false" (e.g., membership in a group, completion of a task).
- Time: Data that represents points or intervals in time (e.g., date, time of day, duration).
- Geographical: Data that represents spatial locations (e.g., latitude, longitude, postal code).
- Text: Data that consists of unstructured textual information (e.g., comments, descriptions, social media posts).
- Images: Data that represents visual information in a digital format (e.g., photographs, screenshots, medical images).
Data Properties:
- Cardinality: The number of distinct values in a dataset.
- Scale: The level of measurement used to classify data into categorical or numerical types.
- Distribution: The pattern of values in a dataset, such as normal, skewed, or bimodal.
- Central tendency: Measures of the center of a dataset, such as mean, median, and mode.
- Variability: Measures of how spread out a dataset is, such as standard deviation and variance.