Do Tags on a web site result in duplicate content

[copywriter39]

I have a client that uses wordpress for their site design and use tags throughout. I know this is done a lot, but they also create additional pages using the tag designation. For example their page widgets.html is tagged for widgets. When you click the tag you are taken to a new page that has the same copy as the first. The only difference is the url is now tags.widget.html. Wouldn't this simply be duplicate copy? And why even do it.

[createdevelop]

I know that some of the SEO plugins have nofollow and noindex as default on all categories and tags for this reason. Obviously, as well as dupe content worries, there are also issues associated with having a page that is just full of links to other pages.

However I think if the page uses the canonical tag like below, you should be ok.

http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html

Sometimes tags and categories have some purpose. For one thing they provide an easy way for people to navigate from your front page to older pages on your website. Also they provide a way to group content that you cant really get any other way.

[dgswilson]

One of those pages will be indexed. Google will tell you in webmaster tools when you have duplicate titles. Most of the time (for me) it has to do with a tag or some other "dynamic link". Google will also tell you if there is anything on your site that is keeping it from being crawled or indexed. You can have a 1000 things wrong and still be crawled and indexed.

Not that you'd want to. You can also, in settings (or robots.txt), tell google not to follow things like "?". I'm not sure of the long term result of this. Maybe someone here will know and tell us. I recently redid my settings statements. I'm still playing around with it and seeing what happens

[NexusSoft]

It is as simple as placing a canonical tag in the head of your duplicate content. Similar to :
<link rel="canonical" href="http://www.example.com/?tag=blah-blah-blah" />

[alienpest]

You can specify your canonical url, as others have mentioned, there is a plugin for that. "All In One SEO" allows you to choose whether you want the tags to be available for indexing or not. You can even choose to do such things as make your tags your meta keywords.

[dgswilson]

That's good advice on the "All In One SEO". Aside from captcha and askimet, it's the only plugin I use.