Add results merge strategy

Author: mattgotteiner

app/backend/approaches/approach.py

@@ -261,6 +261,7 @@ async def run_agentic_retrieval(
         filter_add_on: Optional[str] = None,
         minimum_reranker_score: Optional[float] = None,
         max_docs_for_reranker: Optional[int] = None,
+        results_merge_strategy: Optional[str] = None,
     ) -> tuple[KnowledgeAgentRetrievalResponse, list[Document]]:
         # STEP 1: Invoke agentic retrieval
         response = await agent_client.retrieve(
@@ -298,7 +299,12 @@ async def run_agentic_retrieval(
 
         results = []
         if response and response.references:
-            references = sorted(response.references, key=lambda reference: int(reference.id))
+            if results_merge_strategy == "interleaved":
+                # Use interleaved reference order
+                references = sorted(response.references, key=lambda reference: int(reference.id))
+            else:
+                # Default to descending strategy
+                references = response.references
             for reference in references:
                 if isinstance(reference, KnowledgeAgentAzureSearchDocReference) and reference.source_data:
                     results.append(

app/backend/approaches/chatreadretrieveread.py

@@ -235,6 +235,7 @@ async def run_agentic_retrieval_approach(
         search_index_filter = self.build_filter(overrides, auth_claims)
         top = overrides.get("top", 3)
         max_subqueries = overrides.get("max_subqueries", 10)
+        results_merge_strategy = overrides.get("results_merge_strategy", "interleaved")
         # 50 is the amount of documents that the reranker can process per query
         max_docs_for_reranker = max_subqueries * 50
 
@@ -246,6 +247,7 @@ async def run_agentic_retrieval_approach(
             filter_add_on=search_index_filter,
             minimum_reranker_score=minimum_reranker_score,
             max_docs_for_reranker=max_docs_for_reranker,
+            results_merge_strategy=results_merge_strategy,
         )
 
         text_sources = self.get_sources_content(results, use_semantic_captions=False, use_image_citation=False)

app/backend/approaches/retrievethenread.py

@@ -186,6 +186,7 @@ async def run_agentic_retrieval_approach(
         search_index_filter = self.build_filter(overrides, auth_claims)
         top = overrides.get("top", 3)
         max_subqueries = overrides.get("max_subqueries", 10)
+        results_merge_strategy = overrides.get("results_merge_strategy", "interleaved")
         # 50 is the amount of documents that the reranker can process per query
         max_docs_for_reranker = max_subqueries * 50
 
@@ -197,6 +198,7 @@ async def run_agentic_retrieval_approach(
             filter_add_on=search_index_filter,
             minimum_reranker_score=minimum_reranker_score,
             max_docs_for_reranker=max_docs_for_reranker,
+            results_merge_strategy=results_merge_strategy,
         )
 
         text_sources = self.get_sources_content(results, use_semantic_captions=False, use_image_citation=False)

app/frontend/src/api/models.ts

@@ -27,6 +27,7 @@ export type ChatAppRequestOverrides = {
     seed?: number;
     top?: number;
     max_subqueries?: number;
+    results_merge_strategy?: string;
     temperature?: number;
     minimum_search_score?: number;
     minimum_reranker_score?: number;

app/frontend/src/components/Settings/Settings.tsx

@@ -15,6 +15,7 @@ export interface SettingsProps {
     temperature: number;
     retrieveCount: number;
     maxSubqueryCount: number;
+    resultsMergeStrategy: string;
     seed: number | null;
     minimumSearchScore: number;
     minimumRerankerScore: number;
@@ -55,6 +56,7 @@ export const Settings = ({
     temperature,
     retrieveCount,
     maxSubqueryCount,
+    resultsMergeStrategy,
     seed,
     minimumSearchScore,
     minimumRerankerScore,
@@ -108,6 +110,7 @@ export const Settings = ({
     const retrieveCountFieldId = useId("retrieveCountField");
     const maxSubqueryCountId = useId("maxSubqueryCount");
     const maxSubqueryCountFieldId = useId("maxSubqueryCountField");
+    const resultsMergeStrategyFieldId = useId("resultsMergeStrategy");
     const includeCategoryId = useId("includeCategory");
     const includeCategoryFieldId = useId("includeCategoryField");
     const excludeCategoryId = useId("excludeCategory");
@@ -227,6 +230,24 @@ export const Settings = ({
                 />
             )}
 
+            {showAgenticRetrievalOption && useAgenticRetrieval && (
+                <Dropdown
+                    id={resultsMergeStrategyFieldId}
+                    className={styles.settingsSeparator}
+                    label={t("labels.resultsMergeStrategy")}
+                    selectedKey={resultsMergeStrategy}
+                    onChange={(_ev?: React.FormEvent<HTMLElement | HTMLInputElement>, option?: IDropdownOption) =>
+                        onChange("resultsMergeStrategy", option?.key)
+                    }
+                    aria-labelledby={includeCategoryId}
+                    options={[
+                        { key: "interleaved", text: t("labels.resultsMergeStrategyOptions.interleaved") },
+                        { key: "descending", text: t("labels.resultsMergeStrategyOptions.descending") }
+                    ]}
+                    onRenderLabel={props => renderLabel(props, includeCategoryId, includeCategoryFieldId, t("helpTexts.resultsMergeStrategy"))}
+                />
+            )}
+
             <TextField
                 id={retrieveCountFieldId}
                 className={styles.settingsSeparator}

app/frontend/src/locales/en/translation.json

@@ -84,6 +84,11 @@
         "minimumRerankerScore": "Minimum reranker score",
         "retrieveCount": "Retrieve this many search results:",
         "maxSubqueryCount": "Max subqueries",
+        "resultsMergeStrategy": "Results merge strategy",
+        "resultsMergeStrategyOptions": {
+            "interleaved": "Interleaved",
+            "descending": "Descending"
+        },
         "includeCategory": "Include category",
         "includeCategoryOptions": {
             "all": "All"
@@ -144,6 +149,8 @@
              "Sets the number of search results to retrieve from Azure AI search. More results may increase the likelihood of finding the correct answer, but may lead to the model getting 'lost in the middle'.",
         "maxSubqueryCount":
             "Sets the maximum number of subqueries to use for the agentic retrieval query plan.",
+        "resultsMergeStrategy":
+            "Sets the strategy for merging results from multiple subqueries. Interleaved picks the top results from each subquery in round robin order, while descending sorts all results by reranker score.",
         "includeCategory":
             "Specifies a category to include in the search results. There are no categories used in the default data set.",
          "excludeCategory":

app/frontend/src/pages/ask/Ask.tsx

@@ -31,6 +31,7 @@ export function Component(): JSX.Element {
     const [retrievalMode, setRetrievalMode] = useState<RetrievalMode>(RetrievalMode.Hybrid);
     const [retrieveCount, setRetrieveCount] = useState<number>(3);
     const [maxSubqueryCount, setMaxSubqueryCount] = useState<number>(10);
+    const [resultsMergeStrategy, setResultsMergeStrategy] = useState<string>("interleaved");
     const [useSemanticRanker, setUseSemanticRanker] = useState<boolean>(true);
     const [useSemanticCaptions, setUseSemanticCaptions] = useState<boolean>(false);
     const [useQueryRewriting, setUseQueryRewriting] = useState<boolean>(false);
@@ -139,6 +140,7 @@ export function Component(): JSX.Element {
                         exclude_category: excludeCategory.length === 0 ? undefined : excludeCategory,
                         top: retrieveCount,
                         max_subqueries: maxSubqueryCount,
+                        results_merge_strategy: resultsMergeStrategy,
                         temperature: temperature,
                         minimum_reranker_score: minimumRerankerScore,
                         minimum_search_score: minimumSearchScore,
@@ -199,6 +201,9 @@ export function Component(): JSX.Element {
             case "maxSubqueryCount":
                 setMaxSubqueryCount(value);
                 break;
+            case "resultsMergeStrategy":
+                setResultsMergeStrategy(value);
+                break;
             case "useSemanticRanker":
                 setUseSemanticRanker(value);
                 break;
@@ -350,6 +355,7 @@ export function Component(): JSX.Element {
                     temperature={temperature}
                     retrieveCount={retrieveCount}
                     maxSubqueryCount={maxSubqueryCount}
+                    resultsMergeStrategy={resultsMergeStrategy}
                     seed={seed}
                     minimumSearchScore={minimumSearchScore}
                     minimumRerankerScore={minimumRerankerScore}

app/frontend/src/pages/chat/Chat.tsx

@@ -47,6 +47,7 @@ const Chat = () => {
     const [minimumSearchScore, setMinimumSearchScore] = useState<number>(0);
     const [retrieveCount, setRetrieveCount] = useState<number>(3);
     const [maxSubqueryCount, setMaxSubqueryCount] = useState<number>(10);
+    const [resultsMergeStrategy, setResultsMergeStrategy] = useState<string>("interleaved");
     const [retrievalMode, setRetrievalMode] = useState<RetrievalMode>(RetrievalMode.Hybrid);
     const [useSemanticRanker, setUseSemanticRanker] = useState<boolean>(true);
     const [useQueryRewriting, setUseQueryRewriting] = useState<boolean>(false);
@@ -219,6 +220,7 @@ const Chat = () => {
                         exclude_category: excludeCategory.length === 0 ? undefined : excludeCategory,
                         top: retrieveCount,
                         max_subqueries: maxSubqueryCount,
+                        results_merge_strategy: resultsMergeStrategy,
                         temperature: temperature,
                         minimum_reranker_score: minimumRerankerScore,
                         minimum_search_score: minimumSearchScore,
@@ -316,6 +318,9 @@ const Chat = () => {
             case "maxSubqueryCount":
                 setMaxSubqueryCount(value);
                 break;
+            case "resultsMergeStrategy":
+                setResultsMergeStrategy(value);
+                break;
             case "useSemanticRanker":
                 setUseSemanticRanker(value);
                 break;
@@ -538,6 +543,7 @@ const Chat = () => {
                         temperature={temperature}
                         retrieveCount={retrieveCount}
                         maxSubqueryCount={maxSubqueryCount}
+                        resultsMergeStrategy={resultsMergeStrategy}
                         seed={seed}
                         minimumSearchScore={minimumSearchScore}
                         minimumRerankerScore={minimumRerankerScore}