Introducing the Semantic Dominance Index
The Semantic Dominance Index (SDI) is a composite score — expressed on a 0–100 scale — that measures how prominently and favorably a brand is surfaced and comparatively framed across the answer layer. It is derived from a structured battery of queries run against leading answer engines including ChatGPT, Gemini, Claude, and Grok, scored against a proprietary rubric.
SDI is not a mention count or a sentiment score. It measures whether your brand is surfaced as a default answer, whether it is recommended with or without qualification, whether it is positioned above or below named competitors, and whether the model's characterization is current, credible, and commercially advantageous.
Because LLMs are non-deterministic and outputs vary by session, SDI uses statistical sampling — running structured query batteries multiple times across varying parameters — to isolate the median, recurring verdict. The score reflects stable, probabilistic market realities, not a single output.