American children do much better identifying the correct answers to simple scientific tasks than using evidence from their experiments to explain those answers.
The National Assessment of Educational Progress, often called the Nation's Report Card, asked students in grades four, eight and 12 to perform actual experiments to apply principles they learn in the classroom on a practical level.
In computerized tests, 27 percent of high school seniors could both select and explain their correct answers. Fifty-four percent of eighth graders could support conclusions with evidence. Only 15 percent of fourth graders could do the same.
Girls outperformed boys in almost every category.
The results are from two types of science tests given by the National Center for Education Statistics to 2,000 students in 2009. Results were released Tuesday.