diff --git a/mteb/models/kalm_models.py b/mteb/models/kalm_models.py
index 68f17460c3..02251df44d 100644
--- a/mteb/models/kalm_models.py
+++ b/mteb/models/kalm_models.py
@@ -7,6 +7,7 @@
 
 import numpy as np
 import torch
+
 from mteb.encoder_interface import PromptType
 from mteb.model_meta import ModelMeta
 from mteb.models.instruct_wrapper import InstructSentenceTransformerWrapper
diff --git a/tests/test_evaluators/test_STSEvaluator.py b/tests/test_evaluators/test_STSEvaluator.py
new file mode 100644
index 0000000000..aee3963724
--- /dev/null
+++ b/tests/test_evaluators/test_STSEvaluator.py
@@ -0,0 +1,138 @@
+from __future__ import annotations
+
+import pytest
+
+from mteb.evaluation.evaluators.STSEvaluator import STSEvaluator
+from tests.test_benchmark.mock_models import MockNumpyEncoder
+from tests.test_benchmark.mock_tasks import MockSTSTask
+
+
+# Fixtures
+@pytest.fixture
+def model():
+    return MockNumpyEncoder(seed=42)
+
+
+@pytest.fixture
+def mock_task():
+    task = MockSTSTask()
+    task.load_data()
+    return task
+
+
+def test_output_structure(model, mock_task):
+    """Test that the evaluator returns the expected output structure and scores."""
+    test_data = mock_task.dataset["test"]
+
+    evaluator = STSEvaluator(
+        sentences1=test_data["sentence1"],
+        sentences2=test_data["sentence2"],
+        gold_scores=test_data["score"],
+        task_name="test_sts",
+    )
+    scores = evaluator(model)
+
+    # Check basic structure
+    assert isinstance(scores, dict)
+
+    # Check required metrics
+    assert "pearson" in scores
+    assert "spearman" in scores
+    assert "cosine_pearson" in scores
+    assert "cosine_spearman" in scores
+    assert "manhattan_pearson" in scores
+    assert "manhattan_spearman" in scores
+    assert "euclidean_pearson" in scores
+    assert "euclidean_spearman" in scores
+
+    # Check exact score values with deterministic model
+    assert scores["pearson"] == -1.0
+    assert scores["spearman"] == -0.9999999999999999
+    assert scores["cosine_pearson"] == -1.0
+    assert scores["cosine_spearman"] == -0.9999999999999999
+    assert scores["manhattan_pearson"] == -1.0
+    assert scores["manhattan_spearman"] == -0.9999999999999999
+    assert scores["euclidean_pearson"] == -1.0
+    assert scores["euclidean_spearman"] == -0.9999999999999999
+
+
+def test_basic_functionality(model, mock_task):
+    """Test basic functionality and proper initialization."""
+    test_data = mock_task.dataset["test"]
+
+    evaluator = STSEvaluator(
+        sentences1=test_data["sentence1"],
+        sentences2=test_data["sentence2"],
+        gold_scores=test_data["score"],
+        task_name="test_sts",
+    )
+
+    # Check that data is properly stored
+    assert evaluator.sentences1 == test_data["sentence1"]
+    assert evaluator.sentences2 == test_data["sentence2"]
+    assert evaluator.gold_scores == test_data["score"]
+    assert evaluator.task_name == "test_sts"
+
+
+def test_batch_size_parameter(mock_task):
+    """Test that the batch_size parameter in encode_kwargs works correctly."""
+    from tests.test_benchmark.mock_models import MockNumpyEncoder
+
+    # Create a mock encoder that respects batch_size and tracks batch calls
+    class BatchTrackingMockEncoder(MockNumpyEncoder):
+        def __init__(self, seed=42):
+            super().__init__(seed)
+            self.batch_calls = []  # Track each batch call
+
+        def encode(self, sentences, prompt_name=None, **kwargs):
+            batch_size = kwargs.get("batch_size", 32)
+
+            # Track individual batch calls
+            for i in range(0, len(sentences), batch_size):
+                batch = sentences[i : i + batch_size]
+                self.batch_calls.append(len(batch))
+
+            return super().encode(sentences, prompt_name, **kwargs)
+
+    test_data = mock_task.dataset["test"]
+
+    evaluator = STSEvaluator(
+        sentences1=test_data["sentence1"],
+        sentences2=test_data["sentence2"],
+        gold_scores=test_data["score"],
+        task_name="test_sts",
+    )
+
+    # Test with batch_size=1 - should process texts one at a time
+    tracking_model_1 = BatchTrackingMockEncoder()
+    scores_batch_1 = evaluator(tracking_model_1, encode_kwargs={"batch_size": 1})
+
+    # Calculate expected batch calls
+    num_sentences1 = len(test_data["sentence1"])
+    num_sentences2 = len(test_data["sentence2"])
+
+    # With batch_size=1, each text should be processed in its own batch
+    expected_batch_1_calls = num_sentences1 + num_sentences2
+    assert len(tracking_model_1.batch_calls) == expected_batch_1_calls
+    assert all(batch_size == 1 for batch_size in tracking_model_1.batch_calls)
+
+    # Test with batch_size=2 - should process texts in pairs (mostly)
+    tracking_model_2 = BatchTrackingMockEncoder()
+    scores_batch_2 = evaluator(tracking_model_2, encode_kwargs={"batch_size": 2})
+
+    # Calculate expected batch calls for batch_size=2
+    import math
+
+    expected_batch_2_calls = math.ceil(num_sentences1 / 2) + math.ceil(
+        num_sentences2 / 2
+    )
+    assert len(tracking_model_2.batch_calls) == expected_batch_2_calls
+    # Each batch should have at most 2 items (last batch might have 1)
+    assert all(batch_size <= 2 for batch_size in tracking_model_2.batch_calls)
+    assert all(batch_size >= 1 for batch_size in tracking_model_2.batch_calls)
+
+    # Check that evaluation works with custom batch sizes
+    assert isinstance(scores_batch_1, dict)
+    assert isinstance(scores_batch_2, dict)
+    assert "pearson" in scores_batch_1
+    assert "pearson" in scores_batch_2
diff --git a/tests/test_evaluators/test_SummarizationEvaluator.py b/tests/test_evaluators/test_SummarizationEvaluator.py
new file mode 100644
index 0000000000..f58537d528
--- /dev/null
+++ b/tests/test_evaluators/test_SummarizationEvaluator.py
@@ -0,0 +1,175 @@
+from __future__ import annotations
+
+import pytest
+
+from mteb.evaluation.evaluators.SummarizationEvaluator import SummarizationEvaluator
+from tests.test_benchmark.mock_models import MockNumpyEncoder
+from tests.test_benchmark.mock_tasks import MockSummarizationTask
+
+
+# Fixtures
+@pytest.fixture
+def model():
+    return MockNumpyEncoder(seed=42)
+
+
+@pytest.fixture
+def mock_task():
+    task = MockSummarizationTask()
+    task.load_data()
+    return task
+
+
+def test_output_structure(model, mock_task):
+    """Test that the evaluator returns the expected output structure and scores."""
+    test_data = mock_task.dataset["test"]
+
+    evaluator = SummarizationEvaluator(
+        human_summaries=test_data["human_summaries"],
+        machine_summaries=test_data["machine_summaries"],
+        gold_scores=test_data["relevance"],
+        task_name="test_summarization",
+    )
+    scores = evaluator(model)
+
+    # Check basic structure
+    assert isinstance(scores, dict)
+
+    # Check required metrics
+    assert "pearson" in scores
+    assert "spearman" in scores
+    assert "cosine_pearson" in scores
+    assert "cosine_spearman" in scores
+    assert "dot_pearson" in scores
+    assert "dot_spearman" in scores
+
+    # Check exact score values with deterministic model
+    assert scores["pearson"] == -1.0
+    assert scores["spearman"] == -0.9999999999999999
+    assert scores["cosine_pearson"] == -1.0
+    assert scores["cosine_spearman"] == -0.9999999999999999
+    assert scores["dot_pearson"] == 0.0
+    assert scores["dot_spearman"] == 0.0
+
+
+def test_basic_functionality(model, mock_task):
+    """Test basic functionality and proper initialization."""
+    test_data = mock_task.dataset["test"]
+
+    evaluator = SummarizationEvaluator(
+        human_summaries=test_data["human_summaries"],
+        machine_summaries=test_data["machine_summaries"],
+        gold_scores=test_data["relevance"],
+        task_name="test_summarization",
+    )
+
+    # Check that data is properly stored
+    assert evaluator.human_summaries == test_data["human_summaries"]
+    assert evaluator.machine_summaries == test_data["machine_summaries"]
+    assert evaluator.gold_scores == test_data["relevance"]
+    assert evaluator.task_name == "test_summarization"
+
+
+def test_encode_kwargs_handling(model, mock_task):
+    """Test that encode_kwargs are properly handled."""
+    test_data = mock_task.dataset["test"]
+
+    evaluator = SummarizationEvaluator(
+        human_summaries=test_data["human_summaries"],
+        machine_summaries=test_data["machine_summaries"],
+        gold_scores=test_data["relevance"],
+        task_name="test_summarization",
+    )
+
+    # Test that the evaluator accepts encode_kwargs
+    scores = evaluator(model, encode_kwargs={"batch_size": 16})
+    assert isinstance(scores, dict)
+    assert "pearson" in scores
+
+
+def test_batch_size_parameter(mock_task):
+    """Test that the batch_size parameter in encode_kwargs works correctly."""
+    from tests.test_benchmark.mock_models import MockNumpyEncoder
+
+    # Create a mock encoder that respects batch_size and tracks batch calls
+    class BatchTrackingMockEncoder(MockNumpyEncoder):
+        def __init__(self, seed=42):
+            super().__init__(seed)
+            self.batch_calls = []  # Track each batch call
+
+        def encode(self, sentences, prompt_name=None, **kwargs):
+            batch_size = kwargs.get("batch_size", 32)
+
+            # Track individual batch calls
+            for i in range(0, len(sentences), batch_size):
+                batch = sentences[i : i + batch_size]
+                self.batch_calls.append(len(batch))
+
+            return super().encode(sentences, prompt_name, **kwargs)
+
+    test_data = mock_task.dataset["test"]
+
+    evaluator = SummarizationEvaluator(
+        human_summaries=test_data["human_summaries"],
+        machine_summaries=test_data["machine_summaries"],
+        gold_scores=test_data["relevance"],
+        task_name="test_summarization",
+    )
+
+    # Test with batch_size=1 - should process texts one at a time
+    tracking_model_1 = BatchTrackingMockEncoder()
+    scores_batch_1 = evaluator(tracking_model_1, encode_kwargs={"batch_size": 1})
+
+    # Calculate expected batch calls
+    total_human_texts = sum(len(hs) for hs in test_data["human_summaries"])
+    total_machine_texts = sum(len(ms) for ms in test_data["machine_summaries"])
+
+    # With batch_size=1, each text should be processed in its own batch
+    expected_batch_1_calls = total_human_texts + total_machine_texts
+    assert len(tracking_model_1.batch_calls) == expected_batch_1_calls
+    assert all(batch_size == 1 for batch_size in tracking_model_1.batch_calls)
+
+    # Test with batch_size=2 - should process texts in pairs (mostly)
+    tracking_model_2 = BatchTrackingMockEncoder()
+    scores_batch_2 = evaluator(tracking_model_2, encode_kwargs={"batch_size": 2})
+
+    # Calculate expected batch calls for batch_size=2
+    import math
+
+    expected_batch_2_calls = math.ceil(total_human_texts / 2) + math.ceil(
+        total_machine_texts / 2
+    )
+    assert len(tracking_model_2.batch_calls) == expected_batch_2_calls
+    # Each batch should have at most 2 items (last batch might have 1)
+    assert all(1 <= batch_size <= 2 for batch_size in tracking_model_2.batch_calls)
+
+    # Check that evaluation works with custom batch sizes
+    assert isinstance(scores_batch_1, dict)
+    assert isinstance(scores_batch_2, dict)
+    assert "pearson" in scores_batch_1
+    assert "pearson" in scores_batch_2
+
+
+def test_empty_scores_handling(model, mock_task):
+    """Test that the evaluator handles cases where some samples have equal scores."""
+    test_data = mock_task.dataset["test"]
+
+    # Create a case where some gold scores are identical
+    modified_gold_scores = test_data["relevance"].copy()
+    if len(modified_gold_scores) > 0 and len(modified_gold_scores[0]) > 1:
+        # Make all scores in the first sample identical
+        modified_gold_scores[0] = [modified_gold_scores[0][0]] * len(
+            modified_gold_scores[0]
+        )
+
+    evaluator = SummarizationEvaluator(
+        human_summaries=test_data["human_summaries"],
+        machine_summaries=test_data["machine_summaries"],
+        gold_scores=modified_gold_scores,
+        task_name="test_summarization_equal_scores",
+    )
+
+    # Should still work even with some samples having equal scores
+    scores = evaluator(model)
+    assert isinstance(scores, dict)
+    assert "pearson" in scores