The National Center for Health Statistics put out some numbers on surveying — The general conclusion is that using “landline” only methods for data collection will skew the analysis. Here is a direct link to the report.
The key findings are :

1 in 6 homes (~15%) are “Cell Phone Only” — that is they simply DO NOT have a landline….

The model of engagement on the internet is evolving and so are the means for conducting market research. These are currently the 5 main channels for getting research done online:

Online Surveys – Surveys are and will most likely be the core of conducting research online for the foreseeable future. They are an efficient and cost effective manner for collecting quantifiable data….

It’s almost considered “standard practice” to have a “Progress Bar” — indicator that tells the respondents where they are in a branched or multi-page survey. However, if you think about this for a minute there are a few other strategies that you can use to keep your users engaged :

Single Page Survey — In some cases if you can fit the entire survey into one single scrolling page….

The AFL-CIO launched the “Working Women 2008” survey a few days ago and here is an example of great marketing of the survey itself.
A few key points that I think all of us can learn.

Consistent Brand / Marketing:

Having links to the survey in the footer of the page – to increase awareness: 
There carries into the survey itself

It looks like the AFL-CIO and WorkingAmerica invested some time and though into putting this survey together….

Introduction to your survey
When creating online surveys — there are a broad set of “Do’s” and “Don’ts”. Having an introduction to your survey is not only a “Do” but a “Must Have”. Keep in mind that you are asking your customers, users or partners to spend their time and give you feedback. Think about this for a minute —…