diff --git a/client/__tests__/util/centroid.test.js b/client/__tests__/util/centroid.test.js
new file mode 100644
index 00000000..140b78cd
--- /dev/null
+++ b/client/__tests__/util/centroid.test.js
@@ -0,0 +1,96 @@
+import _ from "lodash";
+
+import calcCentroid from "../../src/util/centroid";
+
+import quantile from "../../src/util/quantile";
+import * as Universe from "../../src/util/stateManager/universe";
+import * as World from "../../src/util/stateManager/world";
+import * as REST from "./stateManager/sampleResponses";
+import { ControlsHelpers as CH } from "../../src/util/stateManager";
+
+describe("centroid", () => {
+  let world;
+  let categoricalSelection;
+  beforeAll(() => {
+    // Create world + universe
+    let universe = Universe.createUniverseFromResponse(
+      _.cloneDeep(REST.config),
+      _.cloneDeep(REST.schema)
+    );
+
+    universe = {
+      ...universe,
+      ...Universe.addObsAnnotations(
+        universe,
+        Universe.matrixFBSToDataframe(REST.annotationsObs)
+      ),
+      ...Universe.addVarAnnotations(
+        universe,
+        Universe.matrixFBSToDataframe(REST.annotationsVar)
+      ),
+      ...Universe.addObsLayout(
+        universe,
+        Universe.matrixFBSToDataframe(REST.layoutObs)
+      )
+    };
+    world = World.createWorldFromEntireUniverse(universe);
+
+    // Create categorical selection from world
+    categoricalSelection = CH.createCategoricalSelection(
+      world,
+      CH.selectableCategoryNames(world.schema, CH.maxCategoryItems(REST.config))
+    );
+  });
+
+  test("field4 (categorical obsAnnotation)", () => {
+    const centroidResult = calcCentroid(
+      world.obsAnnotations,
+      world.obsLayout,
+      "field4",
+      ["umap_0", "umap_1"],
+      categoricalSelection,
+      world.schema.annotations.obsByName
+    );
+
+    // Check to see that a centroid has been calculated for every categorical value
+    const keysAsArray = Array.from(centroidResult.keys());
+    expect(keysAsArray).toEqual(
+      expect.arrayContaining([83, true, "foo", 2.222222])
+    );
+
+    // This expected result assumes that all cells belong in all categorical values inside of sample response
+    const expectedResult = [
+      quantile([0.5], world.obsLayout.col("umap_0").asArray())[0],
+      quantile([0.5], world.obsLayout.col("umap_1").asArray())[0]
+    ];
+
+    centroidResult.forEach(coordinate => {
+      expect(coordinate).toEqual(expectedResult);
+    });
+  });
+
+  test("field3 (boolean obsAnnotation", () => {
+    const centroidResult = calcCentroid(
+      world.obsAnnotations,
+      world.obsLayout,
+      "field3",
+      ["umap_0", "umap_1"],
+      categoricalSelection,
+      world.schema.annotations.obsByName
+    );
+
+    // Check to see that a centroid has been calculated for every categorical value
+    const keysAsArray = Array.from(centroidResult.keys());
+    expect(keysAsArray).toEqual(expect.arrayContaining([false, true]));
+
+    // This expected result assumes that all cells belong in all categorical values inside of sample response
+    const expectedResult = [
+      quantile([0.5], world.obsLayout.col("umap_0").asArray())[0],
+      quantile([0.5], world.obsLayout.col("umap_1").asArray())[0]
+    ];
+
+    centroidResult.forEach(coordinate => {
+      expect(coordinate).toEqual(expectedResult);
+    });
+  });
+});
diff --git a/client/src/util/centroid.js b/client/src/util/centroid.js
index f8c2c801..bbdd021e 100644
--- a/client/src/util/centroid.js
+++ b/client/src/util/centroid.js
@@ -114,5 +114,5 @@ const hashMedianCentroid = (
     categorySelection
   )}:${Object.keys(schemaObsByName)}`;
 };
-// export the mmemoized calculation function
+// export the memoized calculation function
 export default memoize(calcMedianCentroid, hashMedianCentroid);