Investors interested in Schools stocks are likely familiar with GP Strategies (GPX) and TAL Education (TAL). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great grade in the Value category of our Style Scores system. The proven Zacks Rank puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.GP Strategies and TAL Education are sporting Zacks Ranks of #2 (Buy) and #5 (Strong Sell), respectively, right now. This means that GPX's earnings estimate revision activity has been more impressive, so investors should feel comfortable with its improving analyst outlook. But this is only part of the picture for value investors.Value investors also tend to look at a number of traditional, tried-and-true figures to help them find stocks that they believe are undervalued at their current share price levels.Our Value category grades stocks based on a number of key metrics, including the tried-and-true P/E ratio, the P/S ratio, earnings yield, and cash flow per share, as well as a variety of other fundamentals that value investors frequently use.GPX currently has a forward P/E ratio of 17.12, while TAL has a forward P/E of 65.53. We also note that GPX has a PEG ratio of 1.14. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. TAL currently has a PEG ratio of 1.98.Another notable valuation metric for GPX is its P/B ratio of 1.36. The P/B ratio is used to compare a stock's market value with its book value, which is defined as total assets minus total liabilities. For comparison, TAL has a P/B of 4.95.These metrics, and several others, help GPX earn a Value grade of A, while TAL has been given a Value grade of D.GPX sticks out from TAL in both our Zacks Rank and Style Scores models, so value investors will likely feel that GPX is the better option right now.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report GP Strategies Corporation (GPX): Free Stock Analysis Report TAL Education Group (TAL): Free Stock Analysis Report To read this article on Zacks.com click here.