Reading & writing · Grades 10–12
Assumptions in a model · reading guide
An original passage with comprehension, reasoning and a marking guide.
Assumptions in a model
A model predicted that a tank would empty at a constant rate. Its graph was a straight line. In the real experiment, the water level fell quickly at first and more slowly later. The team retained the model as a rough approximation over a short interval, but documented that it did not describe the entire process accurately.
Read, think and respond
- Which assumption differs from the observed behaviour?
- Why might a model remain useful despite being imperfect?
- Describe evidence that would justify replacing the straight-line model.
Suggested answers and marking notes
Which assumption differs from the observed behaviour?
Rubric: Identify constant outflow or constant rate of falling water level, depending on the model interpretation, and connect it to the changing observed rate.
Why might a model remain useful despite being imperfect?
Rubric: Explain that a documented approximation can be adequate within a specified interval or purpose, while limitations prevent overextension.
Describe evidence that would justify replacing the straight-line model.
Rubric: Refer to systematic curved patterns or changing slopes in repeated measurements, with attention to uncertainty rather than isolated noise.
Learning preview · teacher review required. Grade bands are approximate, not official curriculum alignment.