I had the question posed to me:

First and foremost the user should have a good experience. If you always make your decisions based on that then you’ll get it right most of the time. Another thing to keep in mind, and this applies to any user input, only ask what you need to know. If there is something that you want to know but is not essential to the task then don’t ask.

For instance, if you’re working on a site for an online grocery store then resist asking for things like the users favorite vacation destination just so you can target ads to them. I know, I know, you would never do such a thing but believe me, someone in marketing will ask for something equally inappropriate. I find it useful to carry rubber bands with me to meetings like this so that I can shoot people for asking for things like that. :-)

With that said here are a few suggestions:

If the site is all HTML then stick with HTML forms. Conversely, if your site is all Flash then do the forms in Flash.

Go with what you know. If you’re comfortable with one or the other then go with that. You’re more likely to create something that the user likes if you like what you are using to create with. Basically, if you can’t stand working in HTML then by all means, don’t use HTML to create your forms. You’ll be more likely to cut corners just to get it done.

Flash is obviously more expressive that HTML. If you want to create something that goes beyond the typical experience that people have with HTML forms then there’s your answer: Flash.

Advantages to Flash forms:

• You can control the font.
• Both Javascript and Actionscript are equally adept at client side validation. However, in the Flash environment you have more options for providing feedback to the user.
• I would give Flash a slight nod when it comes to maintaining state with the use of Local Objects.

The only intrinsic argument I can think of against Flash forms is the old, “What if they don’t have the Flash player?” cliche. We’ll when you’re doing something that is leveraging the browser DOM heavily your more likely to find people who have browsers that aren’t up to snuff but do have the Flash player.

I think that if you say to yourself, “I want to create the perfect user experience for using my forms.” then you’ll want to go with Flash because of all it offers. But believe me, the Flash part will be easy. The UX (User eXperience) work will be the most time consuming part.

If you do go with Flash then keep in mind what version of the player you are publishing for. If you’re not using anything that requires the latest player then don’t publish for it. Go as low as you can. For a project like this that will likely be version 6 or 7, depending on the code.

Last thoughts, just about anything you can do with Flash forms you can do with HTML/Javascript. However, if you’re really going over the top and manipulating the interface as the user progresses through the forms then the HTML approach is going to become more and more problematic.

With HTML you’re going to have to test in multiple environments. My biggest concern would be how my perfect forms are going to work on browsers in 2-3 years down the road that aren’t even out yet. I’d be in a “Here’s Johnny” mood if I had a bunch of HTML/Javascript that IE7 just took a crap on. With Flash, you’re just about guarantied that what works now will work later.