---
url: "https://questionstar.com/principles-of-survey-research/chapter-5/slide-203.html"
title: "Phi Coefficient"
type: "lehrbuch-slide"
chapter: 5
chapterTitle: "Data Analysis: A Concise Overview of Statistical Techniques"
slide: 203
---

# Phi Coefficient

*The higher φ, the stronger the relationship between the variables.*

![φ = square root of χ² divided by n](/principles-of-survey-research/media/formel_phi.png)

The higher φ , the stronger the relationship between the variables.

Values **> 0.30** are considered substantial.

Problems:

- φ is not standardized and has an upper limit of 1 only for 2×2 tables; it depends on the table dimensions.
- φ values from different studies cannot be compared with one another.

In our example:

![φ = square root of 3.333 divided by 30 = 0.333](/principles-of-survey-research/media/formel_phi_bsp.png)

The relationship is **not particularly strong.**

---

*Slide 203 of 274 · Chapter 5: Data Analysis: A Concise Overview of Statistical Techniques · Principles of Survey Research · Dr. Paul Marx*