Maximal point‐polyserial correlation for non‐normal random distributions
2025

Maximal Point-Polyserial Correlation for Non-Normal Random Distributions

publication Evidence: moderate

Author Information

Author(s): Alessandro Barbiero

Primary Institution: Università degli Studi di Milano

Hypothesis

The study aims to derive the expression for the maximal point-polyserial correlation between a continuous random variable and an ordinal random variable with k categories.

Conclusion

The maximum point-polyserial correlation can be significantly increased by optimizing the scores assigned to the ordinal random variable.

Supporting Evidence

  • The study provides a closed-form formula for the maximal point-polyserial correlation as a function of the probabilities and parameters of the distribution.
  • An algorithm is devised to obtain the maximum value numerically for any given number of categories.
  • The findings are illustrated with real data examples.

Takeaway

This study looks at how to find the best way to measure the relationship between a continuous number and a set of ordered categories, like ratings from 1 to 5.

Methodology

The study derives closed-form formulas for the maximal point-polyserial correlation and uses numerical algorithms to find maximum values for various distributions.

Limitations

The study does not specify the joint distribution of the continuous and ordinal variables, which may affect the results.

Digital Object Identifier (DOI)

10.1111/bmsp.12362

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