A metric is a quantitative measurement of a visitor action. Metrics are what Optimizely uses to measure differences in visitor behavior that occur as a result of changes you make to your site. Metrics measure the success of your experiment by telling you whether an experiment is winning, losing, or inconclusive.
Metrics are created out of events, which directly track actions like clicks, pageviews, form submissions, purchases, and scroll depth. After you create an event and add it to an experiment, you'll decide how it's displayed as a metric.
Let's use a simple example—suppose your site has an Add-to-Cart button. You would use an event to track every time the button is clicked. You would use a metric to measure the percentage of users who added to cart least once, or alternatively the average number of items added per user.
Every Optimizely experiment needs at least one metric. You can add or modify metrics at any time. View the metrics attached to your experiment on the Results page.
Check out our article on the difference between goals, events, and metrics for a more in-depth explanation.
Identifying the right metric is a huge factor in determining whether your experiment will have statistically significant results. See these KB articles:
- Choosing primary vs. secondary metrics
- When to use each type of metric
- Focusing on metrics that matter