The "U.S. TIMSS and PIRLS 2011 Technical Report and User's Guide" provides an overview of the design and implementation of the Trends in International Mathematics and Science Study (TIMSS) 2011 and the Progress in International Reading Literacy Study (PIRLS) 2011 in the United States and the nine participating benchmarking states: Alabama, California, Colorado, Connecticut, Florida, Indiana, Massachusetts, Minnesota, and North Carolina, along with information designed to facilitate access to the U.S. TIMSS and PIRLS 2011 data. The Trends in International Mathematics and Science Study (TIMSS) 2011 is the fifth such study since this international comparison of student achievement was first conducted in 1995. Developed and implemented at the international level by the International Association for the Evaluation of Educational Achievement (IEA), an international organization of national research institutions and governmental research agencies, TIMSS is used to measure trends in the mathematics and science knowledge and skills of fourth- and eighth-graders. TIMSS is designed to align broadly with mathematics and science curricula in the participating countries. The results, therefore, suggest the degree to which students have learned mathematics and science concepts and skills likely to have been taught in school. TIMSS also collects background information on students, teachers, curricula, and schools to allow cross-national comparisons of educational contexts related to student achievement. In 2011, there were 54 countries and 20 other education systems (including all nine benchmarking states) that participated in TIMSS at the fourth- or eighth-grade level, or both. Also referenced here are three additional reports that provide a detailed treatment of TIMSS 2011 from an international perspective. Two of those reports are available in ERIC and are cross referenced at the end of this abstract. The Progress in International Reading Literacy Study (PIRLS) is an international comparative study of student achievement. PIRLS 2011 represents the third such study since PIRLS was first conducted in 2001. Developed and implemented by the International Association for the Evaluation of Educational Achievement (IEA), an international organization of national research institutions and governmental research agencies, PIRLS is used to measure the reading knowledge and skills of fourth-graders over time. PIRLS is designed to align broadly with reading curricula in the participating education systems. The results, therefore, suggest the degree to which students have learned reading concepts and skills likely to have been taught in school. PIRLS also collects background information on students, teachers, schools, curricula, and official education policies to allow cross-national comparison of educational contexts that may be related to student achievement. In 2011, there were 40 countries and 13 other education systems (including Florida) that participated in PIRLS. Titles of two additional companion reports that provide a detailed treatment of PIRLS 2011 from an international perspective published by the IEA are provided here. Those that are available in ERIC are cross referenced at the end of this abstract. Descriptions of data collection activities and their timing within the United States provide a foundation for researchers seeking to understand the detail of the data. These activities are listed in exhibit 1-1 along with the timing of their implementation. The activities are described in detail in chapter 4 of this report. The basic parameters of the design and administration of TIMSS and PIRLS 2011 in the United States are outlined and a more detailed treatment is provided in subsequent chapters of this report. Appended are: (1) State Sampling Tables; (2) State Participation Rates; (3) TIMSS & PIRLS 2011 Recruitment Materials; (4) Informational Materials; (5) Field Staff Training Materials; (6) U.S. Versions of TIMSS and PIRLS 2011 Student, School, Teacher and Curriculum Questionnaires; and (7) TIMSS and PIRLS 2011 Questionnaire Adaptations. [The following companion reports are available in ERIC: (1) "TIMSS 2011 International Results in Mathematics" (Mullis, Martin, Foy, & Arora, 2012) (ED544554); (2) "TIMSS 2011 International Results in Science" (Martin, Michael O.; Mullis, Ina V. S.; Foy, Pierre; Stanco, Gabrielle M.) (ED544560); (3) "Highlights from TIMSS 2011: Mathematics and Science Achievement of U.S. Fourth- and Eighth-Grade Students in an International Context. NCES 2013-009" (ED537756); (4) "PIRLS 2011 International Results in Reading" (Mullis, Martin, Foy, & Drucker, 2012) (ED544362); and (5) "Highlights from PIRLS 2011: Reading Achievement of U.S. Fourth-Grade Students in an International Context. NCES 2013-010" (ED537758).].