Types of Data
- Numerical: Quantitative data that have a median, mean, and variability or spread (e.g., age in years, height in inches, # of words spoken)
- Categorical: Data that groups participants into distinct categories based on certain qualities (e.g., mild-moderate-severe, language spoken).
- Ordinal (type of categorical data): Data that groups participants into distinct categories based on certain qualities and can be ranked in a specific order (e.g., mild-moderatesevere).
- Nominal (type of categorical data): Data that groups participants into distinct categories based on certain qualities and cannot be ranked in a specific order (e.g., language spoken, gender, race).
Types of Statistics
- Descriptive: Types of questions that aim to summarize and describe a variable(s).
- Inferential: Type of questions that aim to test hypotheses and make predictions about variables.
Measures of Central Tendency
Mean: Sum of all measurements divided by the number of measurements.
Median: The number in which half of the measurements are below it and half of the measurements are above it.
Mode: The most frequent measurement in the data.
Measures of Variance
Range: The minimum and maximum values in the data.
Standard Deviation (SD): How much an average each of the values in the distribution varies from the mean of the distribution.
Interquartile Range (IQR): indicator of variance when looking at a boxplot, represents the range in which 25% to 75% of the data fall.
