Unlocking User Delight: How the KANO Model Guides Product Requirement Decisions

KANO Model Overview

The KANO model, introduced by Japanese scholar Noriaki Kano, is a product‑quality management theory widely used in internet product design to evaluate and prioritize product requirements.

Attribute Categories

The model plots attribute satisfaction on the X‑axis and user satisfaction on the Y‑axis, dividing product qualities into five categories: Must‑be (必备属性), One‑dimensional/Expected (期望属性), Attractive (魅力属性), Indifferent (无差异因素), and Reverse (反向属性). As user expectations evolve, an attribute can shift from Attractive to Expected and eventually to Must‑be, as illustrated by the mobile‑internet example.

Practical Implementation

In practice, a KANO questionnaire presents paired positive and negative statements for each feature. Respondents’ answers are classified according to a result‑classification table, allowing teams to identify which features are Must‑be, Expected, Attractive, etc.

Quantitative Analysis with Better‑Worse

Although originally qualitative, scholars have quantified KANO results using Better‑Worse coefficients. The Better coefficient measures the satisfaction gain when an Attractive or Expected feature is added, while the Worse coefficient measures the satisfaction loss when a Must‑be or Expected feature is removed. According to Berger (1993):

<code>better = (Attractive + Expected) / (Attractive + Expected + Must‑be + Indifferent)
worse = - (Expected + Must‑be) / (Attractive + Expected + Must‑be + Indifferent)</code>

These metrics help product teams assess the impact of each feature on overall user satisfaction and guide optimization decisions.