A summary of our purchased and internally developed software as of December 31 is as follows (in thousands):

INCOME TAXES. Income taxes are accounted for using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences of temporary differences between the carrying amounts and tax bases of assets and liabilities using enacted rates.

Annual tax provisions include amounts considered sufficient to pay assessments that may result from examination of prior year tax returns; however, the amount ultimately paid upon resolution of issues raised may differ from the amounts accrued.

The financial statement effects of an uncertain income tax position are recognized when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. Other tax contingencies are accrued for when it is probable that a liability to a taxing authority has been incurred and the amount of the contingency can be reasonably estimated. The current portion of uncertain income tax positions is included in “Income taxes and other” and the long-term portion is included in “Noncurrent income taxes payable” in the consolidated balance sheets.

Provisions are made for taxes on undistributed earnings of foreign subsidiaries and related companies.

COMPREHENSIVE INCOME. Comprehensive income includes any changes in the equity of an enterprise from transactions and other events and circumstances from non-owner sources. Our two components of other comprehensive income are foreign currency translation adjustment and unrealized gains and losses from investments. They are presented on our consolidated statements of stockholders’ investment.

STOCK-BASED COMPENSATION. We account for share-based compensation in accordance with SFAS No. 123R, Share Based Payment. Under this standard, the fair value of each share-based payment award is established on the date of grant. For grants of restricted shares and restricted units, the fair value is established based on the market price on the date of the grant, discounted for post-vesting holding restrictions. The discounts have varied from 12 to 22 percent and are calculated using the Black-Scholes option pricing model. Increased stock price volatility is the primary factor that has caused the change in the discount applied.

For grants of options, we use the Black-Scholes option pricing model to estimate the fair value of share-based payment awards. The determination of the fair value of share-based awards is affected by our stock price and a number of assumptions, including expected volatility, expected life, risk-free interest rate, and expected dividends.