Refer to the exhibit. A data scientist creates a SageMaker Pipeline definition using the JSON shown. The pipeline runs successfully, but the scientist notices that the training step did not use the parameter 'TrainingInstanceCount' defined in Parameters. Why did this happen?
Parameters must be explicitly referenced in steps to take effect.
Why this answer
The SageMaker Pipeline definition shows that the training step's `InstanceCount` field is hardcoded to `1` in the step definition, rather than referencing the `TrainingInstanceCount` parameter using the `Parameters` object (e.g., `Parameters.TrainingInstanceCount`). In SageMaker Pipelines, parameters defined in the `Parameters` section must be explicitly referenced within the step definitions using the `Parameters` object; otherwise, the pipeline uses the hardcoded values and ignores the parameters entirely.
Exam trap
AWS often tests the misconception that simply defining a parameter in the `Parameters` section automatically applies it to all steps, when in reality each step must explicitly reference the parameter using the `Parameters` object.
How to eliminate wrong answers
Option A is wrong because the pipeline ran successfully, and a runtime error would have caused the pipeline to fail, not fall back to default values; SageMaker Pipelines does not silently fall back to defaults on error. Option B is wrong because the parameter name 'TrainingInstanceCount' is spelled identically in both the Parameters section and the step definition, so there is no typo. Option D is wrong because the training image compatibility with the instance type would cause a runtime error during execution, not cause the parameter to be ignored; the pipeline would fail if the image were incompatible.