NEW YORK (CNN/Money) - All that glitters is not gold. With that in mind, let's take another look at Tuesday's report on announced layoffs, which was widely taken as a good number.

"Announced layoffs" are the result of legislation passed in the 1990s that requires larger firms to let their workers -- and the government -- know about three months in advance of plans to cut jobs. Challenger, Gray & Christmas, a Chicago outplacement firm has been tracking them for about 10 years.

The latest tally shows a big drop, to 68,623 in May from 146,399 in April. That's the lowest level in 30 months, and John Challenger says this could signal an end to the massive downsizing by U.S. corporations.

Recently by Kathleen Hays • Take it on faith • Great expectations • Which bull do you buy?

Problem is, you have to compare apples to apples, and a closer look at Challenger data shows that the numbers are always lower in May. In fact, the average number of announced layoffs in the month of May from 1997 to 2000 -- before the economy sank into recession -- was way lower at 37,726.

The May 2003 number is nearly twice that high!

Okay, so let's look at the past six years, from 1997 to 2002, which includes both some boom years and the slowdown and recession years as well. Now we get an average of 49,337 announced layoffs, still a lot lower than the May 2003 total.

So, let's take the latest sign of "improvement" with a grain of salt. If these numbers keep falling, then we can believe that a real turn in the job market is here.

But if this proves to be more of a seasonal shift than a permanent drop, then our hopes for a glittering recovery will tarnish like a piece of cheap silver.

Kathleen Hays anchors The FlipSide, airing Monday to Friday on CNNfn. As part of CNN's Business News team, she is also a regular contributor to Lou Dobbs Moneyline.