How to display hash digests

What textual format should I use for presenting hash digests, to best support human comparison of two hash values?

The standard format is a sequence of hex digits, but I'm not sure whether that is the best choice. The task I want to support is that some person will need to look at two hash values and confirm whether they match. I am especially focused on usability. What format will work best for average people, and maximize the likelihood that they check diligently, and make the comparison process as efficient and effective as possible?

I can imagine many possibilities: e.g., hex, decimal, base64, or a sequence of words from a Diceware/PGP/EFF-style wordlist. The hash value could be one long string of hex digits, or it could be broken into chunks. There are probably other options, too. Is there any evidence for what is most effective? Are there any published user studies on the subject?