A new comparison tool lets you easily find out if funds are what they say they are, be it small-cap or otherwise

The asset allocation theory of portfolio management dictates that you spread out your investment dollars among several different asset classes-- such as small stocks, large stocks, bonds, foreign stocks-- in a particular plan. Using mutual funds, it's easy to divide your investments. Simply buy the right types of funds and your allocation is set.

Or is it? While mutual-fund rating services such as Morningstar.com, Value Line, and The Lipper Funds, Inc. sort funds by objective and category, some funds stray from the definitions used by those services. As a result, you could end up with what looks like a diversified portfolio from the outside, but with an overall asset allocationYou can put this tool to good use in a review of your current fund holdings that varies significantly from your plan.

So how can you tell if your fund is a sheep in wolf's clothing, or, in other words, something other than it appears to be? One way is to use a free online tool you'll find at FindaFund.com. The site's Similarity Portfolio Analysis (SPA) program will compare any two mutual funds and tell you how alike or different the funds are. To use the program, just enter any two fund ticker symbols, and SPA will do the rest.

The tool works by looking at the sector weightings and individual holdings of the funds (each fund's holdings of small, large, and mid-sized growth and value stocks, as well as cash and types of bonds). Then it assigns a Style Diversity Score to the two funds, based on a scale of 1 to 100. SPA also considers the equity sectors (such as utilities, transportation, capital goods, and energy) in which each fund is invested, and assigns a score on that basis as well. The program also lists those stocks held by both funds so you can easily identify any overlap.

The SPA report includes a graphic that gives you a quick visual clue as to how different the funds are. Click this graphic and you can see the underlying data for both funds.

For example, we compared two mutual funds identified by Morningstar.com as "Small Cap Growth" funds, O'Shaughnessy Cornerstone Growth and Berger New Generation. According to FindaFund.com, these two funds have a Style Diversity Score of 99, indicating that they invest in very different types and sizes of companies. It turns out that the O'Shaughnessy fund has invested 7 percent of its portfolio in medium-sized value stocks, while the Berger fund has invested 86 percent of its holdings in small-growth companies. These funds couldn't be any more different in their investment styles, even though they are classified in the same category.

You can put this tool to good use in a review of your current fund holdings. Enter the ticker symbols of your funds