Curriculum based assessment is a method of evaluating student performance by selecting assessment content directly from the materials being taught to students. This means that teachers are assessing precisely what they teach, which can be useful for understanding how well students have understood the material and how well they can apply that knowledge in a testing environment. However, this form of testing does comes with some limitations:
Curriculum based assessment cannot provide generalized performance indicators
One of the biggest limitation of curriculum based assessments are that because performance indicators are tied to exactly what is being taught they cannot give insight into performance across subjects, which is what is often required for more complex critical thinking and problem solving, and they prove to be rather rigid, which can cause problems for assessment if a student changes schools or if the school adopts a new curriculum or even textbook.
Curriculum based assessments struggle to represent success in long term teaching objectives
Curriculum based assessment is focused on assessing understanding of material that has been taught within a semester or school period and this means that it can be quite a short-term representation of student understanding. It can also mean that curriculum based assessment can often struggle to represent long-term progress in broader themes because it requires retrieval of materials taught relatively recently. Benchmark testing can help fill this gap by looking at a broader set of metrics to understand how students have progressed across their entire schooling career, rather than just within a single period.
Curriculum based assessment overlooks skills and capabilities that haven’t been covered in the teaching materials
Curriculum based assessments are limited in their lines of questioning and thematic scope, and can only cover topics that have been touched on in class. This means that curriculum based assessments can often be a better representation of how well an educator teaches their curriculum, rather than the more global skills and capabilities of students in broader themes such as reading or critical thinking as a whole. Benchmarking assessments are a form of standardised tests that can assess school student skills beyond the curriculum and measure students ability to retrieve and apply knowledge without ever having to come across those specific topics in class. This means that any student can take the test and gain valuable knowledge on their skills and relative strengths beyond just their ability to understand the curriculum.
Curriculum based assessment makes it difficult to compare between cohorts that have been taught different materials
While it might be obvious which students are performing better than others in a particular class, it can be much more difficult to understand how that class is doing as a whole compared to other classes or other schools. Benchmarking tests on the other hand are designed to provide insights into how students are doing at the individual, school or even country level making it easier to understand relative performance and where intervention and resources could be most effective to elevate the performance of the entire school.
Curriculum based assessment does not provide insight into the context behind performance outcomes
Context is vital to understanding why a student might be struggling to perform or motivate themselves to learn. Looking at simple test results will tell you whether a student has understood the materials but not necessarily why or what factors might have contributed to the underperformance. That is why some school level benchmarking assessments like the OECD PISA for Schools test also employ post-assessment questionnaires to better understand students’ socioeconomic backgrounds and motivations for learning. This data can provide insight into what kind of factors can affect student performance outside of just the curriculum and teaching methods.