Santa Monica-based Xdrive got $47 million in venture capital funding during the second quarter ended June 30, or maybe it was $26.8 million.

Each of the widely divergent numbers come from a well-respected outfit, PricewaterhouseCoopers LLP and the National Venture Capital Association, respectively.

So, who’s right?

“It was $47 million,” confirms Xdrive founder and Chief Executive Brett O’Brien. “I’m not sure where the other organization got their information. Nobody contacted me.”

In this particular case, the discrepancy may be no more than the result of human error: $26.8 million is the amount of venture funding that Xdrive, an Internet hard drive storage provider, received in two previous rounds of funding. But it is indicative of the differences in the numbers that these organizations tally.

PricewaterhouseCoopers pegged the total amount of venture capital investment in Los Angeles during the most recent quarter at $728.7 million. The NVCA, on the other hand, puts the amount at $979.1 million.

Both PricewaterhouseCoopers and NVCA profess to use mostly the same criteria in determining how much money was invested over a particular time period. Both spend months calling up venture capital companies and their recipients across the country to track down investments. Both say only straight cash-for-equity investment is counted, as opposed to some form of debt financing. Neither counts cases in which a large company puts money into one of its own startups. Still, the numbers differ, sometimes wildly.

“The big difference in the numbers is, we get surveys back from more venture capitalists than (PricewaterhouseCoopers),” said John Taylor, NVCA’s director of research. He sees the 34 percent discrepancy in the L.A. second-quarter total as “probably survey coverage. We’re probably 50 percent higher (in terms of the number of people surveyed).”

His counterpart, for whom Taylor has nothing but praise, begs to differ.

“We have 661 venture capital firms that report directly to us,” said Kirk Walden, PWC’s national director of venture capital research. “The membership of the NVCA is only 325, not to suggest that that’s the only number of venture capitalists surveyed.”

Walden said that the difference probably has more to do with his firm’s insistence on counting money that has been put into a company’s coffers, not just committed, calling his process more rigorous than that of Taylor’s group.

Since the NVCA’s numbers are almost always higher in aggregate that those of PricewaterhouseCoopers, the Xdrive snafu seems to be something of an aberration.

In that particular case, PricewaterhouseCoopers at least has the better documentation. Walden has a record showing that he had a conversation with Xdrive Chief Financial Officer Josh Berman about the amount of money the company received. Taylor had no such record confirming discussions with Xdrive officials.

“It strikes me as an error somewhere,” Taylor said. “They (PWC officials) could make an error, and we could make an error.”