"People" and "animals" and "automobiles" are also collective terms and I never hear anyone say "people is funny" or "animals is hibernating" or "automobiles is for sale." I prefer "The data show an increase" to "The data shows an increase" but I checked several language and grammar websites and whether the word "data" is treated linguistically as a singular or plural seems to be a matter of personal preference. Merriam-Webster says the word "data" is a "plural noun but singular or plural in construction." Wikipedia---always an excellent site to quote from---Wait, what?---says the word is more commonly used as a singular than as a plural but adds, "The debate over appropriate usage continues." The Los Angeles Times treats "data" (and "media") as plurals. Mignon Fogarty, who writes the Grammar Girl column, responds to the question "Is data singular or plural?" by insisting that "both usages are standard."
So....I say "are." You say "is." Are, is. Is, are. Oh, let's call the whole thing off. (My apologies to George and Ira Gershwin.)
