You hear variations of the same concern over and over: “can you please add a way to skip images?” “I wish I had a way to tell you that I’m really unsure on some pictures.” “Some of these are so hard. I’m worried that I’m going to mess up your data!”
If you run an online citizen science project that asks volunteers to classify images, you’ve undoubtedly run into this issue. Your gut tells you that you should accommodate your volunteers and allow them to bypass difficult images or to at least allow them to express their uncertainty. But as long as you are showing each image to multiple volunteers, you should resist this urge. Making your volunteers guess – even when they don’t want to – is a good thing: it increases overall project efficiency and provides you with good data. Reassure your volunteers and tell them that when they guess, they are doing a Good Thing for your project.
I wrote the following for our volunteer community shortly after Snapshot Serengeti [link: http://www.snapshotserengeti.org] was launched in 2012. – Margaret Kosmala
Okay, okay. I hear you. I know it’s really frustrating when you get an image with a partial flank or a far away beast or maybe just an ear tip. I recognize that you can’t tell for sure what that animal is. But part of why people are better at this sort of identification process than computers is that you can figure out partial information; you can narrow down your guess. That partial flank has short brown hair with no stripes or bars. And it’s tall enough that you can rule out all the short critters. Well, now you’ve really narrowed it down quite a lot. Can you be sure it’s a wildebeest and not a buffalo? No. But by taking a good guess, you’ve provided us with real, solid information.