Systems of Frequency Curves - Practical Guide to Frequency Systems

In this review of Systems of Frequency Curves the focus is on practical value for students and applied statisticians who need clear descriptions of historical and usable frequency systems. Revised by Professor Norman Lloyd Johnson from Sir William Elderton's original work, this edition omits the correlation material and expands discussion of additional curve families and surfaces, making it a useful reference for anyone working with Pearson or Gram-Charlier forms. The single biggest reason to buy is the book's continued practical orientation: it explains how to apply classical systems of frequency curves rather than attempt exhaustive theoretical coverage.

Key Features

• Revised edition: A substantial revision by Professor Norman Lloyd Johnson updates Elderton's explanations and incorporates later research where helpful.
• Practical focus: The text emphasizes clear, applied descriptions of the Pearson and Gram-Charlier systems so readers can use these curves in real analyses.
• Expanded curve types: New kinds of frequency curves are described, giving readers a broader set of models to consider.
• Frequency surfaces recast: Treatment of frequency surfaces has been reorganized and broadened to improve clarity and usability.
• Concise scope: The book intentionally avoids encyclopaedic coverage, keeping the material concentrated on practically important systems.

Who It's For

This book is best for graduate students, applied statisticians, and researchers who require a working knowledge of classical frequency curve systems for modeling and interpretation. Its clarity on how Pearson and Gram-Charlier families are used makes it particularly helpful as a methodological reference.

Readers expecting a comprehensive historical encyclopedia of every known curve or a modern textbook covering current computational techniques should look elsewhere; the volume is selective and oriented toward classical, practical descriptions rather than exhaustive modern treatments.

Pros & Cons

Pros

• Clear, practical explanations that make classical frequency systems accessible to applied users.
• Useful expansion of curve types, so readers can consider more modeling options.
• Recast treatment of frequency surfaces improves understanding of multivariate shapes.

Cons

• Correlations material was removed, so the book does not serve readers seeking that coverage.

Specifications

Title	Systems of Frequency Curves
Authors	William Palin Elderton; revised by Norman Lloyd Johnson
Original publication	First edition 1906 (subsequent editions)
Content focus	Pearson and Gram-Charlier systems of frequency curves and surfaces
Scope	Practical descriptions, not encyclopaedic coverage
Material changed	Correlations omitted; new curve types and recast surfaces

Our Verdict

Systems of Frequency Curves remains a valuable, practical reference for those needing solid, applied descriptions of classical frequency systems. It is good value for students and practitioners who want usable explanations of Pearson and Gram-Charlier forms without wading through exhaustive theory; those needing correlation treatments or modern computational examples should supplement it with other texts.

Frequently Asked Questions

Does this edition cover correlation methods?
No, the revised edition omits the original material on correlations and focuses on the frequency curves and surfaces.

Are new curve types included?
Yes, Professor Johnson added descriptions of further kinds of frequency curves beyond the original editions.

Is this book practical or theoretical?
The aim is essentially practical: it provides clear, applied descriptions rather than exhaustive theoretical coverage.