Is "Replicate X visual feature from Y app" a valid acceptance criterion Assume there is a graphically intensive visual feature in app X. It includes dimming out some part of the screen at some point in the program. The story revolves around implementing a similar feature in our app which is of the same genre. The PO insists at adding an acceptance criterion, "achieve the same exact effect as in the reference app". Is that a valid acceptance criterion? How can we know that we have achieved it in terms of the definition of done?

The concept is valid, which is to seek a result based on a reference. But of course it needs to be broken down into measurable points.

For example: the acceptance test will be like:

**Achieve the same exact effect as in screen x in app y in terms of:**

**1\. Dimming effect hex value is #9999**

**2\. Area affected by dimmed light is 70% of the screen**

**3\. Colorful items are in black and white...etc**

The main goal of any acceptance test is to help the team to mark the task or feature done. So it has to be measurable not subjected to personal opinions.