Why should a subtest be discontinued after a student makes four consecutive errors during an individual achievement test?

Discontinuing a subtest after a student makes four consecutive errors is an important practice in individual achievement testing as it indicates that a ceiling level has been reached. When a student fails to answer correctly for a series of items, it suggests that they are unable to perform the tasks required at that level of difficulty. Continuing to present additional items may not yield useful information about the student's capabilities and could lead to frustration for both the student and the educator. By stopping the test at this point, the educator can maintain a more accurate assessment of the student's abilities without pushing them beyond their limits. This approach helps in identifying the highest level of performance the student can achieve, which is crucial for tailoring further instruction and support.