According to bartlett, systematic recall errors and distortions are often caused by intruding on reality, though they can also be credited with memory when appropriately applied.

The answer is: Systematic errors and distortions were due to intrusions of his schematic knowledge.

Explanation:

Systematic errors and distortions were due to intrusions of his schematic knowledge, according to Bartlett.

But the instructions given were vague and many of the distortions disappeared when clear instructions were used. In addition, systematic and schema-induced errors are greater with a longer retention interval because the information in the schemes lasts longer in memory than the information in the text.

The answer is: Systematic errors and distortions were due to intrusions of his schematic knowledge.