Most science teachers are amazed when grading tests and quizzes, often wondering how and why students have reached a conclusion, particularly when students fail to provide a detailed account of their logic. Ideally, a variety of assessments should be used to identify alternate student conceptions or gaps in understanding, particularly when preparing students for state-mandated exams. This article presents a website that uses authentic scenarios to gauge students' problem-solving skills and science knowledge. The IMMEX (interactive multimedia exercises) was developed and created to improve problem-solving skills with medical school students and rapidly expended to K-12 classrooms, including high school science. This software allows teachers to determine how students solve problems, and even pinpoint where students are developing misconceptions. Knowing this information and implementing appropriate intervention allows for more effective teaching and greater student achievement. Overall, these problems provide students with practice that can be pivotal in yielding a successful performance on state-mandated exams. (Contains 5 figures.)