According to eye-tracking research conducted by Nielsen Norman Group, users ignored stock photos or any images that don't contain relevant information. On pages: "18% of the viewing time was spent on the photos, while 82% was spent on the text."
What is the mental model readers go through in the reading process? It is composed of 3 main steps:
1. Selection. Readers try to determine what it is worth reading. It is mainly based on two criteria: centers of interest and geographic proximity.
2. Confirmation. Readers want to make sure they took the right decision while going through the mental exercise of selecting.
3. Actual reading. Readers engage with the first paragraph and drop step by step based on interest.
Reading is an effort. People want to make sure that it is worth their time before engaging with any content. Look at your site data, if you’re still not convinced.
So, in the first step, people are scanning the page to select potential content to read. How? They focus on two elements: images and headlines. Clearly, content driven images are a critical element. If the image contains relevant information and if it is of interest for the potential reader, chances are that this reader will select the article, then read it. Now, if the content of the image does not mean anything clear, chances are extremely low that the reader will engage with the content…except if the headline “saves” the image (but don’t count on it). Why? The brain answers a simple equation:
- if images contain relevant information, articles must contain relevant information
- if image content is not clear, the content of the article is probably not clear, too
Like a good article answers to the five Ws (Who, What, Why, When, Where) and one H (How). A good image/photo should answer to at least two of those elements. Of course the more the better.
In addition, humans are more attracted to some images than others, in this order:
1. Image with REAL people (NOT stock images)
2. Image with animals (NOT stock images)
3. Image with static content
4. Image trying to convey a concept (abstract)
Of course, the content of the image has to be relevant to the page. For example, in an e-commerce site, people are expecting to see products (not people).
Does image size matter? It depends. If relevant, yes. If not, not really. Are color photos more powerful than black and white photos? Again, it depends on the context and the content of the image.
In the context of informing, images are here to… INFORM. Not to decorate the page. Don’t forget captions, they help readers in the selection process and your SEO. Also for SEO, don’t forget to include: metadata and title. And make sure that your headline is INFORMATIVE.