diff --git a/tests/stats/correlation_coefficient/CorrelationCoefficientTest.h b/tests/stats/correlation_coefficient/CorrelationCoefficientTest.h
--- a/tests/stats/correlation_coefficient/CorrelationCoefficientTest.h
+++ b/tests/stats/correlation_coefficient/CorrelationCoefficientTest.h
@@ -35,5 +35,11 @@
 private slots:
     void pearsonCoefficient_data();
     void pearsonCoefficient();
+
+    void kendallCoefficient_data();
+    void kendallCoefficient();
+
+    void spearmanCoefficient_data();
+    void spearmanCoefficient();
 };
 #endif // CORRELATIONCOEFFICIENTTEST_H
diff --git a/tests/stats/correlation_coefficient/CorrelationCoefficientTest.cpp b/tests/stats/correlation_coefficient/CorrelationCoefficientTest.cpp
--- a/tests/stats/correlation_coefficient/CorrelationCoefficientTest.cpp
+++ b/tests/stats/correlation_coefficient/CorrelationCoefficientTest.cpp
@@ -42,8 +42,8 @@
     QVector<double> col1Data = {56, 56, 65, 65, 50, 25, 87, 44, 35};
     QVector<double> col2Data = {87, 91, 85, 91, 75, 28, 122, 66, 58};
 
-    double correlationValue_expected = 0.966;
-    double zValue_expected = 0;
+    double correlationValue_expected = 0.96619424909;
+    double zValue_expected = 0.;
 
     QTest::newRow("Sample 1") << col1Data << col2Data << correlationValue_expected << zValue_expected;
 
@@ -53,8 +53,8 @@
     col1Data = {43, 21, 25, 42, 57, 59};
     col2Data = {99, 65, 79, 75, 87, 81};
 
-    correlationValue_expected = 0.529809;
-    zValue_expected = 0;
+    correlationValue_expected = 0.52980897305;
+    zValue_expected = 0.;
 
     QTest::newRow("Sample 2") << col1Data << col2Data << correlationValue_expected << zValue_expected;
 
@@ -64,8 +64,8 @@
     col1Data = {8, 8, 6, 5, 7, 6};
     col2Data = {81, 80, 75, 65, 91, 80};
 
-    correlationValue_expected = 0.65;
-    zValue_expected = 0;
+    correlationValue_expected = 0.64755960039;
+    zValue_expected = 0.;
 
     QTest::newRow("Sample 3") << col1Data << col2Data << correlationValue_expected << zValue_expected;
 }
@@ -103,8 +103,155 @@
     QDEBUG("Z Value is: " << zValue);
     QDEBUG("Z Value Expected is: " << zValue_expected);
 
-    FuzzyCompare(correlationValue, correlationValue_expected, 0.1);
-    FuzzyCompare(zValue, zValue_expected, 0.1);
+    FuzzyCompare(correlationValue, correlationValue_expected, 1.e-5);
+    FuzzyCompare(zValue, zValue_expected);
+}
+
+void CorrelationCoefficientTest::kendallCoefficient_data() {
+    QTest::addColumn<QVector<double>>("col1Values");
+    QTest::addColumn<QVector<double>>("col2Values");
+    QTest::addColumn<QVector<QString>>("col1Texts");
+    QTest::addColumn<QVector<QString>>("col2Texts");
+    QTest::addColumn<bool>("isDouble");
+    QTest::addColumn<double>("correlationValue_expected");
+    QTest::addColumn<double>("zValue_expected");
+
+    // First Sample
+    // This sample is taken from:
+    //  https://www.statsdirect.com/help/nonparametric_methods/kendall_correlation.htm
+    QVector<double> col1Values = {4, 10, 3, 1, 9, 2, 6, 7, 8, 5};
+    QVector<double> col2Values = {5, 8, 6, 2, 10, 3, 9, 4, 7, 1};
+    QVector<QString> col1Texts;
+    QVector<QString> col2Texts;
+
+    bool isDouble = true;
+
+    double correlationValue_expected = 0.51111114025116;
+    double zValue_expected = 2.05718265659;
+
+    QTest::newRow("Sample 1") << col1Values << col2Values << col1Texts << col2Texts << isDouble << correlationValue_expected << zValue_expected;
+
+    // Second Sample
+    // This sample is taken from:
+    //      https://www.statisticshowto.datasciencecentral.com/kendalls-tau/
+    col1Texts = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L"};
+    col2Texts = {"A", "B", "D", "C", "F", "E", "H", "G", "J", "I", "L", "K"};
+    col1Values = {};
+    col2Values = {};
+
+    correlationValue_expected = 0.84848484848;
+    zValue_expected = 3.84676339286;
+
+    QTest::newRow("Sample 2") << col1Values << col2Values << col1Texts << col2Texts << isDouble << correlationValue_expected << zValue_expected;
+}
+
+void CorrelationCoefficientTest::kendallCoefficient() {
+    QFETCH(QVector<double>, col1Values);
+    QFETCH(QVector<double>, col2Values);
+    QFETCH(QVector<QString>, col1Texts);
+    QFETCH(QVector<QString>, col2Texts);
+    QFETCH(bool, isDouble);
+    QFETCH(double, correlationValue_expected);
+    QFETCH(double, zValue_expected);
+
+    Column* col1;
+    Column* col2;
+
+    if (isDouble){
+        col1 = new Column("col1", AbstractColumn::Numeric);
+        col2 = new Column("col2", AbstractColumn::Numeric);
+
+        col1->replaceValues(0, col1Values);
+        col2->replaceValues(0, col2Values);
+    } else {
+        col1 = new Column("col1", AbstractColumn::Text);
+        col2 = new Column("col2", AbstractColumn::Text);
+
+        col1->replaceTexts(0, col1Texts);
+        col2->replaceTexts(0, col2Texts);
+    }
+
+    QVector<Column*> cols;
+    cols << col1 << col2;
+
+    CorrelationCoefficient correlationCoefficientTest("Kendall's Tau");
+    correlationCoefficientTest.setColumns(cols);
+
+    CorrelationCoefficient::Test test;
+    test = CorrelationCoefficient::Test::Kendall;
+
+    bool categoricalVariable = false;
+    correlationCoefficientTest.performTest(test, categoricalVariable);
+
+    double correlationValue = correlationCoefficientTest.correlationValue();
+    double zValue = correlationCoefficientTest.statisticValue()[0];
+
+    QDEBUG("Correlation Value is " << correlationValue);
+    QDEBUG("Correlation Value Expected is " << correlationValue_expected);
+    QDEBUG("Z Value is: " << zValue);
+    QDEBUG("Z Value Expected is: " << zValue_expected);
+
+    FuzzyCompare(correlationValue, correlationValue_expected, 1.e-7);
+    FuzzyCompare(zValue, zValue_expected, 1.e-7);
+}
+
+void CorrelationCoefficientTest::spearmanCoefficient_data() {
+    QTest::addColumn<QVector<double>>("col1Data");
+    QTest::addColumn<QVector<double>>("col2Data");
+    QTest::addColumn<double>("correlationValue_expected");
+
+    // First Sample
+    // This sample is taken:
+    //      https://statistics.laerd.com/statistical-guides/spearmans-rank-order-correlation-statistical-guide-2.php
+    QVector<double> col1Data = {56, 75, 45, 71, 62, 64, 58, 80, 76, 61};
+    QVector<double> col2Data = {66, 70, 40, 60, 65, 56, 59, 77, 67, 63};
+
+    double correlationValue_expected = 0.67272727272;
+
+    QTest::newRow("Sample 1") << col1Data << col2Data << correlationValue_expected;
+
+    // Second Sample
+    // This sample is taken from:
+    //  https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient
+    col1Data = {106, 86, 100, 101, 99, 103, 97, 113, 112, 110};
+    col2Data = {7, 0, 27, 50, 28, 29, 20, 12, 6, 17};
+
+    correlationValue_expected = -0.17575757575;
+
+    QTest::newRow("Sample 2") << col1Data << col2Data << correlationValue_expected;
+
+}
+
+void CorrelationCoefficientTest::spearmanCoefficient() {
+    QFETCH(QVector<double>, col1Data);
+    QFETCH(QVector<double>, col2Data);
+    QFETCH(double, correlationValue_expected);
+
+    Column* col1 = new Column("col1", AbstractColumn::Numeric);
+    Column* col2 = new Column("col2", AbstractColumn::Numeric);
+
+    col1->replaceValues(0, col1Data);
+    col2->replaceValues(0, col2Data);
+
+    QVector<Column*> cols;
+    cols << col1 << col2;
+
+    CorrelationCoefficient correlationCoefficientTest("Spearman Rank");
+    correlationCoefficientTest.setColumns(cols);
+
+    CorrelationCoefficient::Test test;
+    test = CorrelationCoefficient::Test::Spearman;
+
+    bool categoricalVariable = false;
+
+    correlationCoefficientTest.performTest(test, categoricalVariable);
+
+    double correlationValue = correlationCoefficientTest.correlationValue();
+
+    QDEBUG("Correlation Value is " << correlationValue);
+    QDEBUG("Correlation Value Expected is " << correlationValue_expected);
+
+    FuzzyCompare(correlationValue, correlationValue_expected, 1.e-5);
 }
 
 QTEST_MAIN(CorrelationCoefficientTest)