By any measure, great numbers of people are having trouble paying their mortgages. What is less clear is whether the problem is getting better or worse.

Data released Wednesday showed the mortgage delinquency rate rose in the first quarter to 10.06 percent of all loans outstanding on a seasonally adjusted basis, up from 9.47 percent in the fourth quarter.

But the Mortgage Bankers Association, which published the data, said the jump might be the result of distorting factors that are plaguing other efforts to measure the real estate market on a monthly or quarterly basis.

“Simply put, fundamental market factors may be having a greater influence on the delinquency rates than is normally the case, but mathematical models have difficulty discerning the difference over a short period of time,” the association’s chief economist, Jay Brinkmann, said in a statement.

On an unadjusted basis, the delinquency rate fell sharply to 9.38 percent in the first quarter from 10.44 percent in the previous quarter.

The bankers define delinquency as being at least one payment behind but not yet in foreclosure. The percentage of loans in foreclosure increased slightly in the first quarter to 4.63 percent.

“If mortgage deliquencies are not yet clearly improving, it also appears they are not getting worse,” Mr. Brinkmann said. “However, a bad situation that is not getting worse is still bad.”