Knowledge of structure was regarded to have less to do with comprehending a text than levels of other components such as vocabulary, background knowledge, and reading strategies.
The SDH claims that an absence of grammatical knowledge or lack of processing ability interferes with higher level text comprehension. It is also believed that syntactic awareness assists readers in accomplishing their reading comprehension tasks effectively. One of the conclusions that she reached was that second language reader's text comprehension could not always be predicted by the syntactic complexity of the text. There are some underlying issues that led to apparent contradictions in research findings.