Information density is the amount of information in the form of content that a site visitor is greeted with as soon as he lands on a website or webpage.
The greater the information density, the greater the amount of content a visitor will see on the site or page. Because of this tie-in to content, information density has an immediate impact on a user’s cognitive load, which in turn, has a huge impact on the site’s navigability, usability and user experience.
When designing a website, it’s helpful to think of how much content your user can reasonably handle without being bogged down by it. The more content they encounter, the longer it will take them to complete certain tasks and page goals…since the amount of mental processing power for them to complete tasks and goals drastically rises.
Consider the following scenario:
1) One product page features an image, a headline, a description, the price, a call to action and some reviews.
2) Another product page features several images, a few videos of the product, a bunch of testimonials, ratings, reviews, celebrity endorsements, excessive copy, a headline, subheadings, various calls to action for everything from an email sign up to an “add to cart” button, recommended products for cross and upsell purposes, etc.
Clearly, scenario two is the bad design because it is the epitome of analysis paralysis.