Why does easyCBM only let students take a measure once?
The easyCBM system only lets a student take a measure once because once a student has taken a test the first time, re-taking the test is likely to give an artificially-inflated score (familiarity with the material is likely to result in a higher score that is based more on practice than on actual improvement in knowledge and skill).
How often teachers assess students depends on two key questions: How quickly is it reasonable for teachers to expect to see growth in a particular skill area and how much actual intervention has the student received? In all cases, of course, it is important that the student is actually receiving focused instruction to address their skill deficits if teachers hope to see an improvement in their performance over time. The more difficult the skill being tested, the longer the time should be between testing as students need to receive targeted instruction in order to help them improve their skills.