Defined
Depending on whom you talk to, there is a difference between a web designer and a web developer. These titles are a bit fuzzy in definition, but in general: A web designer uses Photoshop (or whatever) to layout a web page. After approval, that web page is sliced up and sent off to a web developer who ties it together in HTML and CSS.
The major problem
We feel that a designer needs to have a very good grasp of HTML and CSS. For starters, it keeps them out of the trouble of designing something that isn't going to be easy (or possible) to build in HTML. More importantly though, we feel that there is still a lot of aesthetic control in the process of taking a comp into HTML, no matter how much time you spend trying to be perfectly detailed for the developer.
Oftentimes, a designer and developer can work in conjunction, and that sounds great on paper. A lot of people swear that it works, but for us — and for our clients — we feel that there is a lot to be gained by the designer taking on a lot of this responsibility. That is not to say this would be the the case for a mammoth site like newyorktimes.com that is using advanced technology. However, since we don't work with clients at that level, it isn't really a huge problem.
If a designer and developer are working hand in hand to create a site, there is a lot more work that has to be done. The designer has to redline his work (mapping which pixel goes where), they have to design every new page design in Photoshop (we do a lot design on the fly while we're coding), and various other steps that, we feel, are oftentimes overkill. The ability to cut out one more meeting or process makes us a lot more efficient.
The ideal solution
In a perfect world, a designer and developer would work together to create the best solution; both would be fairly literate in each other's job description. However, that rarely happens. We do use traditional developers, but we use them for MySQL, PHP, Ruby on Rails, CMS systems — not coding the shell of our sites. We feel this is the best solution, and it's definitely the fastest, easiest one we've found.
There are times when it's easier to work as a team. But for a lot of projects (even larger projects), we feel one person can do two jobs faster than two people can do two jobs.
At the end of the day...
Part of what makes us good at our job is experience, learning new things, and thinking outside the box. There's a lot to be said about doing one thing, and only one thing, and how you'll get better at your job if that's all you do. We don't really dispute that in a lot of cases, but it's a lot more fun for us if we think of graphic design a lot more like cooking or painting, and a lot less like factory-line assembly. We feel that in our case, knowing basic development skills is what sets us apart (and above).
Beating a dead horse
Most designers agree that to be a good web designer, they need to know the basics of HTML. However, if you're not using HTML, you aren't going to know it well. HTML and CSS have changed substantially in the past few years. Our developers spend their time and expertise on complex, industry-changing projects like creating a PHP/Rails based shopping cart that is better than anything we've ever seen in use. That's the sort of thing they aren't going to have the time to do if they're spending their day writing a code that any qualified designer should be able to do for them.
