DES MOINES, Iowa — Your first-quarter 401(k) statement arrived in the mail, but it remains unopened because you're afraid to see how much more you've lost. You're not alone.

"Investors are going to see that they've continued to contribute in the first quarter and their account still went down," said Dean Kohmann, vice president of 401(k) plan services at Charles Schwab & Co.

"People will need the encouragement and advice to keep doing the right things; keep on investing, keep on taking advantage of your company match."

To determine if your 401(k) is on track, the quick and easy benchmarks to note are the Standard & Poor's 500 stock index, which fell 12 percent during the quarter, and the Dow Jones industrial average, which dropped 13 percent. But there's more to assessing your plan's performance.

For instance, you'll want to look at the specific funds in your portfolio, not just the overall picture. You will need to choose and appropriate benchmarks for each so you're not comparing your fund to an inappropriate index and becoming misguided by the results. This process can help you spot any true laggards and should help educate you on how to make some changes to improve performance.

"The sad reality is people use the wrong benchmark to make decisions," said David Tysk, senior financial adviser with Ameriprise Financial Inc.

One might assume that an appropriate comparison for a large cap stock fund, for example, would be the S&P 500 index, which fell 12 percent in the first quarter after dropping 38 percent in 2008.

If you had, let's say, the Vanguard Large-Cap Index Fund in your 401(k), you could look it up to find it was down 11 percent for the first quarter and 38 percent in 2008. If you're looking at an index fund, you'll want to see similar performance, or look for an explanation.

However, straight comparisons like that are not always accurate indicators for actively managed funds, Tysk said. There could be things happening inside a fund that might not be apparent to an investor without further research. The fund managers could have left, for example, causing performance to drop significantly.