Wilcoxon Test

AAA

DEFINITION of 'Wilcoxon Test'

The Wilcoxon test, which refers to either the Rank Sum test or the Signed Rank test, is a nonparametric test that compares two paired groups. The test essentially calculates the difference between each set of pairs and analyzes these differences. The Wilcoxon Rank Sum test can be used to test the null hypothesis that two populations have the same continuous distribution.


The Wilcoxon Signed Rank test assumes that there is information in the magnitudes and signs of the differences between paired observations. As the nonparametric equivalent of the paired student's t-test, the Signed Rank can be used as an alternative to the t-test when the population data does not follow a normal distribution.







INVESTOPEDIA EXPLAINS 'Wilcoxon Test'

The Rank Sum and Signed Rank tests were both proposed by American statistician Frank Wilcoxon in a groundbreaking research paper published in 1945. The tests laid the foundation for hypothesis testing of nonparametric statistics, which are used for population data that can be ranked but do not have numerical values, such as customer satisfaction or music reviews.

RELATED TERMS
  1. Nonparametric Method

    A method commonly used in statistics to model and analyze ordinal ...
  2. Normal Distribution

    A probability distribution that plots all of its values in a ...
  3. Null Hypothesis

    A type of hypothesis used in statistics that proposes that no ...
  4. T Distribution

    A type of probability distribution that is theoretical and resembles ...
  5. Hypothesis Testing

    A process by which an analyst tests a statistical hypothesis. ...
  6. Policyholder Surplus

    The assets of a mutual insurance company minus its liabilities. ...
Related Articles
  1. Succeeding At The Series 63 Exam
    Professionals

    Succeeding At The Series 63 Exam

  2. How To Evaluate A Company's Balance ...
    Investing Basics

    How To Evaluate A Company's Balance ...

  3. Testing 3 Types Of Analysts
    Personal Finance

    Testing 3 Types Of Analysts

  4. Using Normal Distribution Formula To ...
    Investing Basics

    Using Normal Distribution Formula To ...

comments powered by Disqus
Hot Definitions
  1. Accounts Payable - AP

    An accounting entry that represents an entity's obligation to pay off a short-term debt to its creditors. The accounts payable ...
  2. Ratio Analysis

    Quantitative analysis of information contained in a company’s financial statements. Ratio analysis is based on line items ...
  3. Days Payable Outstanding - DPO

    A company's average payable period. Calculated as: ending accounts payable / (cost of sales/number of days).
  4. Net Sales

    The amount of sales generated by a company after the deduction of returns, allowances for damaged or missing goods and any ...
  5. Over The Counter

    A security traded in some context other than on a formal exchange such as the NYSE, TSX, AMEX, etc. The phrase "over-the-counter" ...
  6. Earnings Before Interest After Taxes - EBIAT

    A financial measure that is an indicator of a company's operating performance. EBIAT, which is equivalent to after-tax EBIT ...
Trading Center