Second Brain — Personal Information Retrieval Console

SECOND/BRAIN

personal information-retrieval console

α semantic 0.50

ASK

try:

SOURCE FILTER

RESULTS OVER TIME

ENTITY GRAPH

peopleprojectstopics

click a node to pivot search

HOW IT WORKS

KEYWORD — BM25 (k1=1.2, b=0.75) over a real inverted index.
SEMANTIC — LSA: 32-dim truncated SVD of the tf-idf matrix, cosine in latent space. Computed in this browser at load — a toy model running real math, not an embeddings API.
HYBRID — α·semantic + (1−α)·keyword, min-max normalized.
RERANK — second pass: 0.6·stage-1 + 0.2·term coverage + 0.15·proximity + 0.1·entity match.
ASK — extractive: top sentences from top docs, cited to sources.