Multimodal Distribution
- A distribution with more than one peak (mode), indicating multiple frequently occurring values or groups.
- Often arises when distinct subgroups exist within the data (e.g., sexes, grade bands).
- Can complicate analysis but reveals subgroup structure useful for interpretation.
Definition
Section titled “Definition”Multimodal distribution refers to a type of data distribution that has multiple peaks or modes. This means that there is more than one value or group of values that occur most frequently in the data set.
Explanation
Section titled “Explanation”A multimodal distribution displays two or more local maxima (peaks or modes) in its frequency or density. These multiple peaks typically reflect the presence of distinct subgroups or categories within the data, each contributing one of the modes. Multimodal patterns are common in real-world data because they reflect the diversity and complexity of underlying populations. While they lack the single, symmetric pattern of distributions such as the normal distribution, multimodal distributions can provide insight into separate groups or clusters present in the data.
Examples
Section titled “Examples”Heights of adults
Section titled “Heights of adults”If a study on the heights of adult males and females is conducted and the plotted data show two peaks—one for the average height of males and another for the average height of females—this is an example of a multimodal distribution because there are two distinct groups of values that occur most frequently.
Classroom grades
Section titled “Classroom grades”In a class of 30 students, collecting grades for a particular assignment may produce a plotted distribution with three peaks—one for students who scored an A, one for students who scored a B, and one for students who scored a C. This is a multimodal distribution because there are three distinct groups of values that occur most frequently.
Other real-world examples
Section titled “Other real-world examples”Examples include studies where income levels show peaks for different income brackets or occupational groups, and surveys where political views produce peaks corresponding to different political parties or ideologies.
Notes or pitfalls
Section titled “Notes or pitfalls”- Multimodal distributions can be challenging to analyze and interpret because they lack the clear and distinct pattern found in other types of distributions, such as the normal distribution.
- Despite this difficulty, they can provide valuable insights by highlighting the presence of multiple subgroups or categories within the data, aiding a deeper understanding of trends and patterns.
Related terms
Section titled “Related terms”- Normal distribution