We have described how to consider the external world when designing a website, both technologically and from a user perspective. It is also important to test your designs against the external world. In the next chapter, we discuss how to test with users. Here, we will briefly look at testing internally on different technologies. Simulating the real world, where your website will be experienced, is crucial when testing your designs.
Gibson's accessibility matrix is useful to guide the testing. Wherever you have different input/output combinations, you should test them. You can add devices, operating systems, and browsers to this matrix to complete the test suite. For example, you may begin with screen reader as an option, then note exactly which screen reader(s) you tested against. If differences emerge with other readers, you can add them as separate items for your next design/test cycle.
There are many tools that help performance, accessibility...