WSJ.com: The Numbers Guy

The one point of widespread agreement in the real-estate industry is that there is no single accurate index of home prices.

Pollsters accurately forecast Tuesday's election results. But pulling off a repeat in 2012 will require overcoming a new set of challenges.

You can fill out brief online questionnaires and get a precise number for your life expectancy, but don't expect the results to be accurate.

In the past decade, articles have lamented the declining proportion of black players in the major leagues. But the numbers appear to be way off.

Election mathematicians, crunching the numbers like never before, are showing that the chance of an electoral tie is greater than you think.

As Top 100 word lists abound. Word-frequency rankings are part of the vast output from studies of language corpora.

If a human year really were equivalent to seven dog years, then people would reach reproductive age by seven, and some would live past 150.

In 40 years, every single American could be overweight, according to a recent study. Employing that same logic, 13 out of every 10 adult Americans by then won't have landlines.

The big mainstream media and polling experts have shunned presidential polls conducted by computers. But these automated polls are proving to be every bit as accurate as other, widely reported polls.

Which states have been hardest hit by the mortgage crisis? It depends on who is doing the counting, and how. Data providers of foreclosure numbers use different methods and have different goals, ma...