Recently on the SIGIA-L list, a discussion broke out on whether or not logos on web sites should be linked to the site's home page. Here's my analysis:
There are a few underlying questions:
- Do users expect logos to be linked to the home page rather than just being a graphical logo?
- Can a linked logo replace another link labeled "home"?
- Does placement of the logo matter (e.g. is top-left better)?
- If a logo is a link, where would users expect it to go?
- A purely graphical logo is great, but a linked logo provides some additional functionality at little cost.
- *I think* most users, *when seeing that a logo is a link*, will expect it to go to the site's home page - there are few other logical places for it to go. (related to question 4)
- I've seen some users click on logos, but most will choose a "home" link first when looking to go "home." (related to questions 1 & 2) Therefore...
- You need to have an explicit "home" link - a logo isn't explicit enough. (related to question 2)
- Placement always matters - but if you think of the logo-link as a supplementary link to the "home" link, then it's not that critical from a navigation point of view - it's likely more important from a branding and context point of view. (related to question 3)
Some related research:
Examining User Expectations for the Location of Common E-Commerce Web Objects
(If you agree that most site's put their logo top-left, then you can draw the conclusion that most users expect logos to be links home.)