XML 58 R17.htm IDEA: XBRL DOCUMENT v2.4.0.6
Stock-Based Compensation
3 Months Ended
Apr. 01, 2012
Stock-Based Compensation [Abstract]  
Stock-Based Compensation

J. Stock-Based Compensation

Restricted stock unit awards granted to employees vest in equal installments over four years. A portion of the restricted stock unit awards granted to executive officers is subject to service-based vesting and a portion of the awards is subject to performance-based vesting. The percentage level of performance satisfied for performance-based grants is assessed on or near the anniversary of the grant date and, in turn, that percentage level determines the number of performance-based restricted stock units available for vesting over the vesting period; portions of the performance-based grants not available for vesting are forfeited. Service-based stock options vest in equal installments over four years, and have a term of seven years from the date of grant.

During the three months ended April 1, 2012, Teradyne granted 1.5 million of restricted stock unit awards to employees at a weighted average grant date fair value of $16.88 and 0.2 million of service-based stock options to executive officers at a weighted average grant date fair value of $6.85.

During the three months ended April 3, 2011, Teradyne granted 1.5 million of restricted stock unit awards to employees at a weighted average grant date fair value of $16.23 and 0.1 million of service-based stock options to executive officers at a weighted average grant date fair value of $6.74.

 

The fair value of stock options was estimated using the Black-Scholes option-pricing model with the following assumptions:

 

     For the Three Months
Ended
 
     April 1,
2012
    April 3,
2011
 

Expected life (years)

     3.50        4.00   

Interest rate

     0.4     1.5

Volatility-historical

     56.0     52.1

Dividend yield

     0.0     0.0

Teradyne determined the stock options' expected life based upon historical exercise data for executive officers, the age of the executive officers and the terms of the stock option grant. Volatility was determined using historical volatility for a period equal to the expected life. The risk-free rate was determined using the U.S. Treasury yield curve in effect at the time of grant.

The weighted-average fair value of employee stock purchase rights granted in the first three months of 2012 and 2011 was $4.09 and $3.66, respectively. The fair value of the employees' purchase rights was estimated using the Black-Scholes option-pricing model with the following assumptions:

 

     For the Three Months
Ended
 
     April 1,
2012
    April 3,
2011
 

Expected life (years)

     0.5        0.5   

Interest rate

     0.06     0.14

Volatility-historical

     52.6     41.0

Dividend yield

     0.0     0.0