RetrievalScoreAdjuster

Use RetrievalScoreAdjuster in your query pipelines to adjust the document scores assigned by EmbeddingRetriever or Ranker.

RetrievalScoreAdjuster adjusts the scores assigned to documents by EmbeddingRetriever or Ranker. It can undo score adjustments EmbeddingRetriever or Ranker made and apply new score scaling using the sigmoid function. You can customize what raw score is the midpoint (50% score) and how spread out you want the scores to be.

Basic Information

  • Pipeline type: Used in query pipelines
  • Nodes that can precede it in a pipeline: Used after Retriever, Ranker
  • Nodes that can follow it in a pipeline: Retriever, Ranker, Reader, PromptNode
  • Input: Documents
  • Output: Documents
  • Available node classes: RetrievalScoreAdjuster

Usage Example

Here's how you could configure RetrievalScoreAdjuster and use it in a pipeline:

components:
  - name: DocumentStore
    type: DeepsetCloudDocumentStore # The only supported document store in deepset Cloud
    params:
      similarity: cosine
  - name: Retriever # Selects the most relevant documents from the document store
    type: EmbeddingRetriever # Uses one Transformer model to encode the document and the query
    params:
      document_store: DocumentStore
      embedding_model: intfloat/multilingual-e5-base # Model optimized for semantic search
      model_format: sentence_transformers
      top_k: 20 # The number of results to return
  - name: Reranker
    type: SentenceTransformersRanker
    params:
      model_name_or_path: svalabs/cross-electra-ms-marco-german-uncased # German-language re-ranker
      top_k: 10
      scale_score: false
  - name: RetrievalScoreAdjuster
    type: RetrievalScoreAdjuster
    params:
      midpoint: 2
      spread_factor: 1.5
      ...
      
 pipelines:
  - name: query
    nodes:
      - name: Retriever
        inputs: [Query]
      - name: Reranker
        inputs: [Retriever]
      - name: RetrievalScoreAdjuster
        inputs: [Reranker]
        ...

Parameters

Here are the parameters you can pass to RetrievalScoreAdjuster in pipeline YAML:

ParameterTypePossible ValuesDescription
undo_scale_scoreBooleanTrue
False
Default: False
Unscales the scores assigned by EmbeddingRetriever or Ranker using the logit function.
Mandatory.
scale_scoreBooleanTrue
False
Default: True
Rescales the scores using the sigmoid function.
Mandatory.
midpointFloatDefault: 0.0Specifies the midpoint value for scaling score. The midpoint value is the value mapped to 50%. Used if scale_score=True.
Mandatory.
spread_factorFloatDefault: 1.0If scale_score=True, pushes scores closer or farther away from 50%. A higher spread factor results in scores closer to 0% or 100%. A lower spread factor results in scores closer to 50%. This value must be greater than 0.
Mandatory.
top_spread_factorFloatDefault: NoneIf scale_score=True, pushes scores that are above midpoint closer or farther away from 100%. A higher top spread factor results in scores closer to 100%, while a lower top spread factor results in scores closer to 50%. This value must be greater than 0.
top_spread_factor takes precedence over spread_factor if both are specified.
Optional.
bottom_spread_factorFloatDefault: NoneIf scale_score=True, pushes scores that are below midpoint closer or farther away from 0%. A higher bottom_spread_factor results in scores closer to 0%. A lower bottom_spread_factor results in scores closer to 50%. This value must be greater than 0.
bottom_spread_factor takes precedence over spread_factor if both are specified.
Optional.
thresholdFloatDefault: NoneSets a threshold for document score. If set, only documents above this threshold (after all adjustments) are returned.
Optional.