Technology in the classroom is a goal that has shown few results. However, high school students in Houston, Texas, USA, have begun to receive artificially intelligent digital textbooks that may actually create results and are programmed to measure those results. The books are initially programmed to instruct mathematics and physics. The books measure the student's progress and the make adjustments according to how the student is doing. The books can provide additional explanations to the students in areas they are having problems. Because the books can change they are referred to as 'adaptice textbooks'. The books also use a learning method called retrieval practice "in which material that students have already learned pops up again in occasional quizzes. This method has been shown to enhance students' ability to retain material, and the algorithmic textbooks will be able to decide when to ask questions based on past exercises." The books will help teachers collect data on how the students are doing and identify patterns.