What are the effects of duplicate content?

Question

I am working on a web design project. My client would like to duplicate certain content above and below the fold. I am concerned about the usability impact - but I can't articulate why.

I have already explained that the fold is not a major barrier so long as a user is engaged, and it is clear that the page may be scrolled (that is, it doesn't have horizontal bar design elements). But they are still keen, because the content is easily monetized, though I fear duplicate content could be harmful.

In this case, I don't think users will believe there's some hidden difference between the two groups of content (which is good in some ways). Nor do I think this will have a significant SEO impact. But I do worry that users won't perceive a consistent and well-organized content model, and that will make it harder for them to navigate and understand the page generally.

Has anyone had any experience with the effects of duplicate content in usability tests? What sorts of issues does it raise (if any)?

Answer 1

Actually, redundancy is not bad.

(...) enhance the quality of content and balance the quantity [by] removing content (unwanted redundancy) and adding content (desired redundancy). It's like an intersection having two or more traffic lights (desired redundancy).

Redundancy is a HCI design principle:

Redundancy gain. If a signal is presented more than once, it is more likely that it will be understood correctly. This can be done by presenting the signal in alternative physical forms (e.g. color and shape, voice and print, etc.), as redundancy does not imply repetition.

So, in fact, if the message to convey is important, redundancy is another mechanism to make it stand out (as vivid colors or big fonts can be). Learning abilities improve when people are presented with multiple forms of the same information.

In other cases, like elder users, it may be a usability or accessibility mesure. This paper talks about "Redundancy in interface design and its impact on intuitive use of a product in older users."

Answer 2

My suggestion when clients want to do this is to map all the content on a given page back to a user goal.

If they keep core tasks "above the fold", then it becomes a diminishing return if they choose to duplicate something.

Another risk I have seen is when clients want to duplicate navigation sections, which becomes a sever usability risk as site visitors see the duplicated content and then have to stop, and try and determine whether the content is any different from the one they just saw a few pixels above.