Management excludes from our non-GAAP measures certain recurring items to facilitate its review of the comparability of our core operating performance on a period-to-period basis because such items are not related to our ongoing core operating performance as viewed by management. Management considers our core operating performance to be that which can be affected by our managers in any particular period through their management of the resources that affect our underlying revenue and profit-generating operations during that period. Management uses this view of our operating performance for purposes of comparison with our business plan and individual operating budgets and allocation of resources. Additionally, when evaluating potential acquisitions, management excludes the items described above from its consideration of target performance and valuation. More specifically, management adjusts for the excluded items for the following reasons:

• Amortization charges for our purchased and other identified intangible assets are inconsistent in amount and frequency and are significantly impacted by the timing and magnitude of our acquisition transactions. We therefore consider our operating results without these charges when evaluating our core performance. Generally, the most significant impact to inter-period comparability of our net income (loss) is in the first twelve months following an acquisition.
• Special charges are incurred based on the particular facts and circumstances of acquisition and restructuring decisions and can vary in size and frequency. These charges are not ordinarily included in our annual operating plan and related budget due the unpredictability of economic trends and the rapidly changing technology and competitive environment in our industry. We therefore exclude them when evaluating our managers' performance internally.
• We view equity plan-related compensation as a key element of our employee retention and long-term incentives, not as an expense that we use in evaluating core operations in any given period. Management also believes this information is useful to investors to compare our performance to the performance of other companies in our industry who present non-GAAP results adjusted to exclude stock compensation expense.
• Interest expense attributable to net retirement premiums or discounts on the early retirement of debt, the write-off of associated debt issuance costs and the amortization of the debt discount on convertible debt were excluded. Management does not consider these charges as a part of our core operating performance. The early retirement of debt and the associated debt issuance costs are not included in our annual operating plan and related budget due to unpredictability of market conditions which could facilitate an early retirement of debt. We consider the amortization of the debt discount on convertible debt recorded under FSP APB 14-1 not to be a direct cost of operations. We also believe this presentation is more useful to investors in comparing our performance to the performance of other companies in our industry who present non-GAAP results adjusted to exclude such items.
• Impairment of cost method investments can occur when the fair value of the investment is less than its cost. This can occur when there is a significant deterioration in the investee’s earnings performance, significant adverse changes in the general market conditions of the industry in which the investee operates, or indications that the investee may no longer be able to conduct business. These charges are inconsistent in amount and frequency. We therefore consider our operating results without these charges when evaluating our core performance.
• Equity in income or losses of unconsolidated subsidiaries represents the net income (losses) in an investment accounted for under the equity method. The amounts represent our equity in the net income (losses) of a common stock investment. The carrying amount of our investment is adjusted for our share of earnings or losses of the investee. The amounts were excluded as we do not influence or control the results of operations for these investments and management does not consider this activity a part of our core operating performance.
• Income tax expense (benefit) is adjusted by the amount of additional tax expense or benefit that we would accrue if we used non-GAAP results instead of GAAP results in the calculation of our tax liability, taking into consideration our long-term tax structure. We use a normalized effective tax rate of 17%, which reflects the weighted average tax rate applicable under the various tax jurisdictions in which we operate. This non-GAAP weighted average tax rate is subject to change over time for various reasons, including changes in the geographic business mix and changes in statutory tax rates. Our GAAP tax rate for the three months ended April 30, 2009 is (27%), after the consideration of discrete items. Without discrete items of $(2,037) thousand, our GAAP tax rate is (47%). Inclusive of discrete items, our full fiscal year 2010 GAAP tax rate is projected to be (48%). The GAAP tax rate considers certain mandatory and other non-scalable tax costs which may adversely or beneficially affect our tax rate depending upon our level of profitability.