diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 592c8ef..87159dd 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -12,10 +12,6 @@ jobs:
     strategy:
       matrix:
         include:
-          - scala-version: 2.11.8
-            spark-version: 2.3.0
-          - scala-version: 2.11.8
-            spark-version: 2.4.3
           - scala-version: 2.12.11
             spark-version: 3.0.0
           - scala-version: 2.12.11
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 581487c..2c83c83 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -12,10 +12,6 @@ jobs:
     strategy:
       matrix:
         include:
-          - scala-version: 2.11.8
-            spark-version: 2.3.0
-          - scala-version: 2.11.8
-            spark-version: 2.4.3
           - scala-version: 2.12.11
             spark-version: 3.0.0
           - scala-version: 2.12.11
diff --git a/python/setup.py b/python/setup.py
index e26acea..8a858d9 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -18,7 +18,7 @@
     long_description=long_description,
     long_description_content_type="text/markdown",
     python_requires=">=3.6",
-    install_requires=["pyspark>=2.3.0", "numpy"],
+    install_requires=["pyspark>=3.0.0", "numpy"],
     tests_require=["pytest"],
     project_urls={
         "Source code": "https://github.com/Salmon-Brain/dead-salmon-brain/tree/main/python",
diff --git a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/BaseStatisticTransformer.scala b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/BaseStatisticTransformer.scala
index d9997c2..48f37ff 100644
--- a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/BaseStatisticTransformer.scala
+++ b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/BaseStatisticTransformer.scala
@@ -35,12 +35,11 @@ trait BaseStatisticTransformer
 
   override def transformSchema(schema: StructType): StructType = outputSchema
 
-  def srm(controlSize: Int, treatmentSize: Int, alpha: Double): Boolean = {
+  def srm(controlSize: Int, treatmentSize: Int): Double = {
     val uniform = (treatmentSize + controlSize).toDouble / 2
     TestUtils.chiSquareTest(
       Array(uniform, uniform),
       Array(controlSize, treatmentSize),
-      alpha
     )
   }
 
diff --git a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/ExpData.scala b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/ExpData.scala
index c9cab85..1205eee 100644
--- a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/ExpData.scala
+++ b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/ExpData.scala
@@ -19,6 +19,8 @@ case class StatisticsReport(
     beta: Double,
     minValidSampleSize: Int,
     srm: Boolean,
+    srmAlpha: Double,
+    pValueSrm: Double,
     controlSize: Long,
     treatmentSize: Long,
     testType: String,
diff --git a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/MannWhitneyStatisticsTransformer.scala b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/MannWhitneyStatisticsTransformer.scala
index 1e05a63..9bb318f 100644
--- a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/MannWhitneyStatisticsTransformer.scala
+++ b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/MannWhitneyStatisticsTransformer.scala
@@ -70,15 +70,17 @@ class MannWhitneyStatisticsTransformer(override val uid: String) extends BaseSta
               beta,
               useLinearApproximationForVariance
             ),
-            srm(controlSize, treatmentSize, $(srmAlpha))
+            srm(controlSize, treatmentSize)
           )
-        else (getInvalidStatResult(CentralTendency.MEDIAN), false)
+        else (getInvalidStatResult(CentralTendency.MEDIAN), -1d)
 
       StatisticsReport(
         statResult,
         alpha,
         beta,
         minValidSampleSize,
+        srmResult < $(srmAlpha),
+        $(srmAlpha),
         srmResult,
         controlSize,
         treatmentSize,
diff --git a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/OutlierRemoveTransformer.scala b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/OutlierRemoveTransformer.scala
index fd452b8..65bd9fc 100644
--- a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/OutlierRemoveTransformer.scala
+++ b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/OutlierRemoveTransformer.scala
@@ -39,15 +39,34 @@ class OutlierRemoveTransformer(override val uid: String)
     set(upperPercentile, value)
 
   override def transform(dataset: Dataset[_]): DataFrame = {
-    assert($(lowerPercentile) > 0 && $(lowerPercentile) < 1, "lowerPercentile must be in (0, 1)")
     assert($(upperPercentile) > 0 && $(upperPercentile) < 1, "upperPercentile must be in (0, 1)")
     assert(
       $(upperPercentile) > $(lowerPercentile),
       "upperPercentile must be greater than lowerPercentile"
     )
 
+    val isDisabledLower = $(lowerPercentile) <= 0
+
     import dataset.sparkSession.implicits._
 
+    val aggFunc = Seq(
+      callUDF("percentile_approx", col($(valueColumn)), lit($(upperPercentile))) as "rightBound"
+    ) ++
+      (if (isDisabledLower) Seq()
+       else
+         Seq(
+           callUDF(
+             "percentile_approx",
+             col($(valueColumn)),
+             lit($(lowerPercentile))
+           ) as "leftBound"
+         ))
+    val filterFunc =
+      if (isDisabledLower) col($(valueColumn)) < $"rightBound"
+      else col($(valueColumn)) > $"leftBound" && col($(valueColumn)) < $"rightBound"
+
+    val dropCols = if (isDisabledLower) Seq("rightBound") else Seq("rightBound", "leftBound")
+
     val columns = Seq(
       $(variantColumn),
       $(experimentColumn),
@@ -59,14 +78,14 @@ class OutlierRemoveTransformer(override val uid: String)
     val percentilesBound = dataset
       .groupBy(columns.head, columns: _*)
       .agg(
-        callUDF("percentile_approx", col($(valueColumn)), lit($(lowerPercentile))) as "leftBound",
-        callUDF("percentile_approx", col($(valueColumn)), lit($(upperPercentile))) as "rightBound"
+        aggFunc.head,
+        aggFunc.tail: _*
       )
 
     dataset
       .join(broadcast(percentilesBound), columns)
-      .filter(col($(valueColumn)) > $"leftBound" && col($(valueColumn)) < $"rightBound")
-      .drop("leftBound", "rightBound")
+      .filter(filterFunc)
+      .drop(dropCols: _*)
   }
 
   override def copy(extra: ParamMap): Transformer = defaultCopy(extra)
diff --git a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/WelchStatisticsTransformer.scala b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/WelchStatisticsTransformer.scala
index 7df5b56..10c3172 100644
--- a/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/WelchStatisticsTransformer.scala
+++ b/ruleofthumb/src/main/scala/ai/salmonbrain/ruleofthumb/WelchStatisticsTransformer.scala
@@ -52,14 +52,17 @@ class WelchStatisticsTransformer(override val uid: String) extends BaseStatistic
         if (isEnoughData)
           (
             WelchTTest.welchTTest(control, treatment, alpha, beta),
-            srm(controlSize.toInt, treatmentSize.toInt, $(srmAlpha))
+            srm(controlSize.toInt, treatmentSize.toInt)
           )
-        else (getInvalidStatResult(CentralTendency.MEAN), false)
+        else (getInvalidStatResult(CentralTendency.MEAN), -1d)
+
       StatisticsReport(
         statResult,
         alpha,
         beta,
         minValidSampleSize,
+        srmResult < $(srmAlpha),
+        $(srmAlpha),
         srmResult,
         controlSize,
         treatmentSize,
diff --git a/ruleofthumb/src/test/scala/ai/salmonbrain/ruleofthumb/OutlierRemoveTransformerSpec.scala b/ruleofthumb/src/test/scala/ai/salmonbrain/ruleofthumb/OutlierRemoveTransformerSpec.scala
index da53668..a070223 100644
--- a/ruleofthumb/src/test/scala/ai/salmonbrain/ruleofthumb/OutlierRemoveTransformerSpec.scala
+++ b/ruleofthumb/src/test/scala/ai/salmonbrain/ruleofthumb/OutlierRemoveTransformerSpec.scala
@@ -11,4 +11,10 @@ class OutlierRemoveTransformerSpec extends AnyFlatSpec with SparkHelper with Mat
     val clearData = new OutlierRemoveTransformer().transform(data)
     assert(clearData.count() == 26)
   }
+
+  "OutlierRemoveTransformerSpec with 0 lower percentile" should "be" in {
+    val data = generateDataForWelchTest()
+    val clearData = new OutlierRemoveTransformer().setLowerPercentile(0).transform(data)
+    assert(clearData.count() == 28)
+  }
 }