Q: On the topic of 1 photo on the cover, could you point me towards the data on that?
I’m very interested in the details on that.
A: Greg Marsello suggested that I might be able to help you with your question. The point of using one large photo as opposed to multiple small images is important in two ways. One is that unless the designer is very skilled, multiple small images may fracture the reader's ability to attend to a central focal point, and may cause the brochure cover to have reduced impact. Also, many programs that use multiple images, use different images in an effort to demonstrate the diversity of their program. The result is that often the images fail to demonstrate much of anything. The second point is that when using multiple images, they are often either two small, or create too much clutter on the page. If the page is cluttered, the reader will not spend much time looking at it, and that is bad for your program.
It is possible to use multiple images to create one, overall image or focal point, but it requires a skilled graphic designer to do this. Here is a link to some additional information that might be of interest.