HEART framework
HEART is a framework for user-centered metrics developed at Google to track progress towards goals for consumer (B2C) web applications. It helps product teams decide how to measure the impact of design changes, set the Overall Evaluation Criteria for A/B tests and track user behaviour changes at large scale. The HEART framework is user-centered instead of business centered, so it focuses primarily on the delivered value part of the value exchange loop.
The framework classifies metrics in five categories, and is named based on the initial letters of the categories: Happiness, Engagement, Adoption, Retention, and Task success. It combines attitudinal and behavioral metrics, and puts them in the context of specific user and product goals.
- Happiness should contain attitudinal metrics capturing how users feel about a product or feature, and it can be tracked by an in-product user survey.
- Engagement should contain behavioral metrics, usually around “frequency, intensity or depth of interaction”
- Adoption should contain metrics that track the number of new users starting to use the product or feature within a period
- Retention should contain metrics that track how users from a given time period are still present later
- Task Success should contain behavioral metrics that track how long it takes for users to complete a key task, the percentage of tasks completed and error rates.
The HEART framework was developed by Kerry Rodden, Hilary Hutchinson, and Xin Fu at Google.
From Goals to Metrics
The HEART framework does not specify individual metrics, but instead categories of metrics that need to be tracked. Product teams are supposed to use the framework to define specific metrics in each category to track progress towards the goals. Rodden, Hutchinson and Fu suggest identifying product goals first, then considering what kind of signals would indicate the progress towards the goals, and finally derive metrics from those goals.
In How to choose the right UX metrics for your product, Rodden provides an example of using the HEART framework for YouTube.
- Goal: users should enjoy the videos they watch, and keep discovering new videos and channels they want to watch
- Signals: Number of videos watched by a user, time spent by a user watching videos
- Metrics: The average number of minutes spent watching videos per user per day.
The key idea with the HEART framework is to make the metrics context-specific and provide deeper insight for product decisions compared to traditional web performance and activity metrics. For example, the authors of the framework point out that tracking adoption and retention separately provides significantly better information about new feature adoption than the traditional metric of Daily Active/Monthly Active users.
Different product changes might require different focus in the HEART framework, so in some cases you may not need to set metrics in all five categories.
Applicability and limitations
The HEART framework was primarily developed for user metrics in consumer products (B2C) at large scale. It does not cover business metrics (value capture from the market), and it may not work as well for smaller-scale user measurements.
For in-house or enterprise software, with a captive audience, some categories such as happiness might not be as important as task success, and adoption and retention may not be relevant at all. There are several less popular frameworks that were inspired by HEART, applicable to those different contexts. One notable example is CASTLE developed at the NN/g.
Learn more about the HEART framework
- Measuring the User Experience on a Large Scale: User-Centered Metrics for Web Applications, CHI Conference on Human Factors in Computing Systems, Atlanta, Georgia, USA by Kerry Rodden, Hilary Hutchinson, Xin Fu (2010)
- How to choose the right UX metrics for your product by Kerry Rodden (2015)