Which term describes a summary of existing literature without a systematic methodological approach?

The correct choice is the narrative review. A narrative review is characterized by its qualitative approach to summarizing and synthesizing existing literature on a particular topic. Unlike systematic reviews, which follow a rigorous and methodical process for identifying, selecting, and analyzing studies, narrative reviews typically do not adhere to such strict criteria. Instead, they provide a broader overview of findings and theories, often emphasizing the author's interpretation of the literature rather than a comprehensive aggregation of quantitative data.

This flexibility allows for the inclusion of a wide range of sources and perspectives, making narrative reviews valuable for generating insights, discussing theoretical frameworks, or identifying gaps in the literature. However, this can also lead to potential biases since the selection of studies included is less structured, impacting the reliability of the conclusions drawn.