As earnings season continues, a negative surprise from a company can crush its stock. But how can you tell in advance whether a stock you own is likely to take a hit from an earnings shortfall?

Past performance may not guarantee future results, but companies that haven't been consistent about matching or beating earnings estimates are logical candidates to expect future negative surprises. So I took a look at the 30 stocks in the Dow Jones Industrials (INDEX: ^DJI) to find out which ones had the least consistent records of delivering on earnings quarter after quarter.

The stocks
As you might expect from the industry leaders that make up the Dow, most Dow stocks do a good job of hitting estimates. But four stocks had missed estimates at least twice over the four quarters leading up to this earnings season. Let's take a closer look at them.

United Technologies (NYSE: UTX) missed estimates three times over the past year. But earlier this week, the company finally came through with a nice earnings beat. Although its revenue fell slightly, the big challenge for United Technologies will come in trying to digest its acquisition of Goodrich and deal with defense-budget cuts that could hurt its aircraft-engine business.

Travelers (NYSE: TRV) had also missed three times on the EPS front, although in most of those cases, disaster-related catastrophe losses were largely to blame for the shortfalls. The company rebounded sharply during the first quarter, beating estimates by nearly $0.50 per share as Travelers was able to boost prices on its insurance offerings without a big offsetting loss in customers.

For Alcoa (NYSE: AA), two missed quarters over the past year seemed to fit with the difficulties the company has had in a tough pricing environment. But the aluminum maker got the current earnings season off on the right foot, turning an expected loss into a profit, as the company proved able to weather the industry's difficulties and maintain its leadership role.

Finally, Wal-Mart (NYSE: WMT) has missed estimates in each of the past two quarters. Few believe that the company's Mexican bribery scandal will hurt its financial results much when Wal-Mart gives its first-quarter report in mid-May, but the retail giant has had difficulty in producing growth over the past several years.

Keep looking at earnings
As we've seen so far this quarter, just because a company misses on earnings in one quarter doesn't mean it won't beat the next. But one thing's certain: you have to keep your eyes open to see what's happening with your stocks.

That's the thinking behind the Motley Fool's special report on earnings, which identifies five stocks that investors simply have to watch this earnings season. The report is free, so let me invite you to click here and get the scoop today.