of a reporting unit’s goodwill exceeds its implied fair value, then we would record an impairment loss equal to the difference.

 

Determining the fair value of a reporting unit involves the use of significant estimates and assumptions. These estimates and assumptions include revenue growth rates and operating margins used to calculate projected future cash flows, risk-adjusted discount rates, future economic and market conditions and determination of appropriate market comparables. We base our fair value estimates on assumptions we believe to be reasonable but that are unpredictable and inherently uncertain. Actual future results may differ from those estimates. In addition, we make certain judgments and assumptions in allocating shared assets and liabilities to determine the carrying values for each of our reporting units. Our most recent annual goodwill impairment analysis, which was performed during the fourth quarter of fiscal 2009, did not result in an impairment charge, nor did we record any goodwill impairment in fiscal 2008 or 2007.

 

We make judgments about the recoverability of purchased intangible assets whenever events or changes in circumstances indicate that an other than temporary impairment may exist. Each period we evaluate the estimated remaining useful lives of purchased intangible assets and whether events or changes in circumstances warrant a revision to the remaining periods of amortization. In accordance with FASB Statement No. 144, Accounting for the Impairment or Disposal of Long-Lived Assets , recoverability of these assets is measured by comparison of the carrying amount of the asset to the future undiscounted cash flows the asset is expected to generate. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset.

 

Assumptions and estimates about future values and remaining useful lives of our intangible and other long-lived assets are complex and subjective. They can be affected by a variety of factors, including external factors such as industry and economic trends, and internal factors such as changes in our business strategy and our internal forecasts. Although we believe the historical assumptions and estimates we have made are reasonable and appropriate, different assumptions and estimates could materially impact our reported financial results. We did not recognize any intangible asset impairment charges in fiscal 2009, 2008 or 2007.

 

Accounting for Income Taxes

 

Significant judgment is required in determining our worldwide income tax provision. In the ordinary course of a global business, there are many transactions and calculations where the ultimate tax outcome is uncertain. Some of these uncertainties arise as a consequence of revenue sharing and cost reimbursement arrangements among related entities, the process of identifying items of revenues and expenses that qualify for preferential tax treatment, and segregation of foreign and domestic earnings and expenses to avoid double taxation. Although we believe that our estimates are reasonable, the final tax outcome of these matters