Virtual keyboard is a graphic user interface for inputting characters by tapping. All touch-screen devices and some mobile devices use a virtual keyboard. Nowadays, social network is becoming more popular. Using Thai virtual keyboard for social network is not efficient. It is difficult to find and type characters because there are many Thai characters in a keyboard layout. This research presents optimization method for designing a Thai virtual keyboard. Social network is our domain specific. Data from social network are used in design, test and evaluation. Fitts' law is used as a metric for estimating typing time. New Thai virtual keyboard layout is designed by applying genetic algorithm. Our layout is evaluated and compared with other layouts. The result shows that our layout yields better.
