The paper investigates whether Internet experiments are an appropriate alternative to traditional laboratory experiments. For an economic experiment of individual decision making results obtained over the Internet are compared to results obtained in the laboratory using exactly the same software. Of particular interest are differences in individual behavior. Our main findings are: (1) running our own experiment on the Internet and in the laboratory generated similar data when economic decision behavior is concerned. (2) Variance in economic decision behavior is generally higher on the Internet experiment. (3) Decision times are shorter on the Internet. (4) Internet software provides a helpful platform for implementing economic experiments. The paper also reports on design challenges and how we have solved them.