The ever insightful Jonathan Christopher recently posted an excellent article on the usability problems with Lightbox, to which I added a response. I did in fact go ahead with some quick usability testing in my office. Here’s what I observed about thumbnail galleries and Lightbox:

• My average user (i.e. one that has very little interest in computers but uses one at work) took a long time to figure out what to do when presented with a thumbnail gallery. More technically inclined users (in this case those active on Facebook and/or Twitter) understood that they were meant to click on a thumbnail in order to see a larger image
• Only one of my five guinea pigs understood that they could move on to the next larger image in the gallery by clicking on the right hand side of the image (Lightbox doesn’t show pagination links until the user hovers over the image)
• All users understood (or guessed very quickly) that clicking outside of the image would return them to the thumbnail page
• No one attempted to use the back button to return to the thumbnail page
• Everyone was impressed with the slideshow feature (even the Facebook and Twitter users who had seen it before: to them it was conventional)

Obviously unscientific, but useful nonetheless. I’m not doubting Jonathon’s findings: I didn’t have much time to do the testing and I probably jumped in a bit early.

There are some pretty big usability problems with javascript slideshows, regardless of the HTML they spit out and the degree to which they do(n’t) degrade gracefully.

Here’s how I altered the page design:

• I added some explanatory text above the thumbnail gallery
• I added a hover state to the thumbnail links
• I used a Lightbox variation that displayed pagination links by default

Second round of testing tomorrow.