Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2018

Schedule of Estimated Fair Value of TSR Performance-Based Restricted Stock Unit Awards Assumptions

The fair value was estimated using the Monte Carlo simulation model with the following assumptions:

	For the Nine Months Ended
	September 30, 2018			October 1, 2017
Risk-free interest rate		2.2	%		1.5	%
Teradyne volatility-historical		26.8	%		26.6	%
NYSE Composite Index volatility-historical		12.4	%		13.4	%
Dividend yield		0.8	%		1.0	%

Fair Value of Stock Options Using Assumptions

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

	For the Nine Months Ended
	September 30, 2018			October 1, 2017
Expected life (years)		5.0			5.0
Risk-free interest rate		2.4	%		2.0	%
Volatility-historical		26.4	%		27.8	%
Dividend yield		0.8	%		1.0	%