This morning a good conversation broke out in Twitter, which is not the best medium for real-time conversation, but hey we take what we get. It was concerning this article where Lukas Mathis said that for people who design user experiences, knowing how to code is detrimental to your ability to produce quality, user-centric designs. I greatly disagreed with his article, and we then had a conversation on Twitter spanning many dozens of Tweets.

If you haven't already read his article please do so, then pop back here.

Designers Don't Just Make The Pretty

A user experience designer designs the user experience, obviously... but is it really that obvious? What's the user experiencing when we say "the user experience"? On the web, there are many things that contribute to the user's overall experience using the website or application:

• Look & feel of the application
• Ability of the user to accomplish the tasks they set out to accomplish
• The overall perceived speed of the website or web application
• Expectations being met. If a user thinks X will happen and it doesn't, there's a gulf of execution

These are just a small sampling. So what's part of a quality user experience? Everything is.

The user's experience with your website or application isn't just what the app looks like or what happens when a user clicks a button. It's not just the workflow they navigate through to execute a task. It's everything. Everything that the user does and experiences from the moment they load up your website or application to the moment they leave it is part of the overall user experience. A user experience designer's job is very important and requires having knowledge of many things in order to be effective.

What Should A User Experience Designer Know?

Designing the user's overall experience is not the same as designing the user interface, it's a lot more than that. In my mind, a user experience designer's job includes user interface design, includes designing the workflow to complete tasks and accomplish goals, includes being knowledgeable about usability testing, includes being knowledgeable about accessibility and users with special needs, and includes having knowledge about how the underlying application architecture works.

The best user experience designers are the ones that bring in knowledge from multiple disciplines (design, development, psychology) and put it all together so that the user benefits.

For example, in my Twitter conversation with Lukas, I gave the example of a UX designer needing to know how Ajax works in order to use it effectively. If you don't know how Ajax works or how web server requests work, how can you decide that in a particular situation Ajax would be best for the user's experience? Lukas replied with this tweet:

That's a perfect example of ignoring the code for a better user experience; page refresh would be easier and quicker to implement.

As I pointed out in my next tweet, what Lukas said is actually not true — in many circumstances an Ajax request is literally faster to execute than a full page refresh. Refreshing the full page makes more HTTP requests to the server (to pull CSS & Javascript files, images) however an Ajax request is only sending back a block of text in many circumstances, so it makes far fewer roundtrip requests to the web server. In most cases, an Ajax request to send data and get data back is faster than a full page refresh.

How do I know that? Because as someone who designs the user experience for web applications, I know how HTTP requests work and how Apache responds to a browser's request, I know about what happens at most places within the roundtrip to the server, and I know about what code is executing server-side when I make an Ajax request. I need to know about these things in order to make the call to use Ajax in a certain scenario over a page refresh. Most often when I decide to use Ajax it's because it will simply be faster and will make the application appear more responsive to the user. A big part of the overall user experience is how the user perceives the speed of the application, so I made a user-centered decision to use Ajax because I know it will enhance a user's experience.

If someone only knows how Ajax works from a superficial standpoint ("something happens without the page refreshing"), then when the choice is made to use Ajax instead of a page refresh, that decision is made without full knowledge of how Ajax works, what it's good for, what it's not good for, how it affects application performance, how it impacts application caching infrastructure, etc. It's a decision made without full knowledge of the consequences.

A Master Designer Knows His Tools

Architects don't just draw blueprints, they need to know what the ground is like under the building, what types of weather the region receives, and what building materials work best considering all the variables. They don't just draw, the craft the entire structure, and need a deep understanding of materials and processes in order to effectively do their job.

Chefs don't just put ingredients together and hope for a delicious dish, they have a deep knowledge of food and how things taste to people in certain situations.

Potters aren't just sculpting clay blocks into beautiful forms, but also firing the clay to keep it in its shape forever. They need to know about glazes and temperature and the science of firing in order to create their works of art.

User experience designers on the web need to know the environment and medium too, just like architects, chefs, and potters. A web designer is someone who designs for the web and knows the HTML & CSS needed to make their designs into real interfaces. If they don't know HTML & CSS, then they're not really designing for the web because they're not designing for the constraints of the medium. So what happens when someone who considers themselves a web designer doesn't have an in-depth knowledge of the medium? They make poor decisions. Decisions made without full knowledge of how their decision impacts the overall user experience. Here's a scenario:

Designer A hands HTML & CSS developer B a mockup of an interface. It's a complex interface and every single corner of every box in the design is rounded and has 3 different borders on it, plus a drop shadow. Every typeface in the mockup is a font the designer just bought, not any default web fonts that users will have.

In this scenario, because the designer isn't familiar with the constraints of the web, they are making design choices that negatively impact the quality of the user's overall experience. To execute rounded corners on a box — one that will expand with the content inside of it — you need additional HTML markup, CSS, and images to make it happen. Multiple borders and border styles? That's more markup and images. Drop shadows? That's a whole bunch of extra transparent PNGs. Custom fonts? You're either using a Flash image replacement method of dynamically-generated images for each one.

Tons of additional markup, images, Flash files, and Javascript just to execute an effect that doesn't make anything better or simpler for the user. Many more kilobytes of data needed to be loaded by the user before they can see the page as it was intended. Additional milliseconds or seconds of load time just because a designer with no knowledge of the web medium didn't design with the environment or constraints of the medium in mind.

Does this mean you can't execute a beautiful interface on the web? Of course not, look at how many beautiful websites and web applications are out there that also work beautifully, too. But a graphically heavy website or web application that is bulky and slow? That has visual effects that don't better the overall user experience? That's not so beautiful, and that's not how you design for the web.

You Don't Gotta Be An Expert

To understand how an Ajax request works you don't need to be able to write the Javascript needed for an Ajax request by hand off the top of your head, or wax technical on Apache process handling, but you do need to understand it fully enough so that you can make educated decisions about its usage. Architects don't choose one material over another just because one looks cooler, they make the decision based on many factors like structural rigidity, price, regional scarcity, etc. They know enough about the material to make an educated decision about whether to use it.

A user experience designer on the web needs to know enough about the environment and the web medium to make quality, user-centric decisions. If a UX designer wants to use a complicated interaction paradigm like drag-and-drop, then they should know the programatic constraints of its usage on the web. Drag-and-drop on the web isn't like drag-and-drop in a desktop app, so you have to know why it's different, how it's different, and how to correctly use drag-and-drop in order to effectively implement it. If you're obsessed with your application's speed then knowledge about how many kilobytes of Javascript it takes to implement DnD is important. You also have to be knowledgeable about how an impaired person uses the web and how to make a drag-and-drop experience still usable for them. You have to know how to handle a situation where a user has Javascript turned off.

Making what seems to simply be a "design decision" never is. It's a decision based on numerous factors encompassing design, development, architecture, usability, and accessibility. A user experience designer's job is to make decisions based on the entire scenario and environment in order to be as effective as possible. Benefiting a user's experience in one aspect, while negating that benefit in another, is the result of not being knowledgeable enough about what you're deciding.

...But It Helps To Be An Expert

Having sufficient knowledge to make a good, user-centric decision is great, but having a more in-depth, advanced knowledge is the best scenario. If you're a user experience designer and you want to use drag-and-drop in an interface, it helps if you can prototype the full interaction to get a feel for the timing and overall experience of the feature. There are some things you just can't know about until you're using a real, live interface, and it's extremely valuable to be able to build a prototype of a real interface to flush those things out early in the design process.

As Apple's operating systems have evolved, so too have their paradigms for user interaction. In Leopard and in many newer Apple applications, animations and advanced user interaction scenarios are used as part of the overall user experience. If a UX designer at Apple has no idea how CoreAnimation works at any level, and they can't use an application like Keynote or Flash to at least prototype an animation effect, then they can't truly express their vision for an interface. In fact, Visual Interface Designers at Apple are expected to know either Flash or Keynote in order to prototype their interfaces. Wait... an interface designer is expected to know how to code ActionScript in order to do their job? Yup, and if you don't, you can't be as effective as other interface designers on your team who do.

Take a look at the folks who are creating cutting-edge Mac and iPhone applications — they're designers with intimate knowledge of how their interfaces are implemented and developed. Designers who are learning Cocoa so they can prototype iPhone interfaces since the key component of good iPhone application design isn't just the visual design, but the interaction. These are the folks who are most successful on the iPhone — the ones who know both design and development and are intimately aware of the constraints of both. Look at the iPhone! It's tiny, low-powered, and doesn't have a keyboard. The entire device is one big constraint, so you have to know what these constraints are to be successful on the platform.

What's A User Experience Designer Mean To You?

There are so many titles for what people do on the web nowadays it's just ludicrous. You've got interface designers, interface engineers, visual interface designers, UI developers, information architects and user experience designers. Then you've got usability engineers, usability testers, web designers, and web developers. With so many titles, and so many people whose skills span a variety of these separate disciplines, where does one know where a UX designer stops and a UI developer begins?

All I can discuss is what's made me more successful in my career, and that's learning as much as possible about the medium in which I work. On the web that means I design workflows, interaction scenarios, interface design mockups, full HTML/CSS/Javascript prototypes, and occasionally implement these prototypes into the backend and hook it up to a database. I started out designing for the web and knowing HTML and Javascript, then I learned CSS, jQuery & Prototype libraries, then PHP, MySQL and some Ruby. I continued my education wherever possible because it's impossible to be too familiar with something when you're trying to make the most educated decision you possibly can. The more information you have access to, real-life experience you can fall back on, and in-depth knowledge you have the better your overall decisions are and the better and more user-friendly your websites and web applications are.

You can't be too knowledgeable when making an important, user-facing decision. The more knowledge you have the more likely it is that you'll see a decision from all possible sides.