In Unit 6 of this course
you are introduced to the concept of quality control.
Quality control is a process that applies to all sorts of goods and services.
Whenever a product is produced or service is provided,
it is important for the product or service to be of good quality.
This concept applies to websites just as it applies to other products.
Quality control can involve very detailed and sophisticated analyses
of the process by which websites are produced,
but it can also be a relatively simple process
of simply testing the quality of the website you've created.
In this unit you'll be testing web pages using automated tools called validators
that check web pages for coding errors.
The W3C provides validators for several markup languages, including HTML...
and CSS.
These validators are easy to use, and provide three ways to test a web page.
You can enter the URL or web address of the page you want to check...
Or if you want to check a private web page that doesn't have a public web address...
you can upload your HTML or CSS file...
Or you can copy and paste your code directly into the validator form.
The hard part about using a validator is understanding the error messages it gives you.
A typical error message in the HTML validator
includes the line number where the error occurs, and a description of the error.
In this case, we have an image on our web page but forgot to include an alt attribute.
Often if you can fix the first error...
that has a cascading effect and the other errors down the line will no longer be flagged as errors.
So a good strategy is to fix one error at a time, then revalidate.
Understanding these validators gets easier with practice.
Validating your HTML and your CSS is important because doing so helps to increase the likelihood
that your page will display consistently across all browsers and platforms.
It's also important to check your site for accessibility.
There are a variety of free accessibility checkers available, including WAVE...
FAE, and many more.
Some accessibility issues can be automatically detected.
In this example, FAE reports that eight image elements don't have an ALT attribute...
Some accessibility issues cannot be automatically detected.
For example, just because you've provided alternate text for your images
doesn't mean you've provided good alt text.
For issues that require human judgment...
accessibility checkers will simply provide a warning that prompts you to double-check those issues manually
to be sure you have them right.
While it's important to ensure your website has valid code and complies with accessibility standards,
a site that passes all these tests can still be poorly designed.
Another aspect of quality control is asking questions like:
Can users easily find what they're looking for on the site?
Can they use the site for its intended purpose?
To answers these sorts of questions
there's no substitute for observing actual users as they interact with your website.
This is called usability testing
and this unit includes an opportunity for you to experience that process and learn how it's done.