diff --git a/tests/testthat/test-mlclassificationboosting.R b/tests/testthat/test-mlclassificationboosting.R
index 2e85154c..21d66b2b 100644
--- a/tests/testthat/test-mlclassificationboosting.R
+++ b/tests/testthat/test-mlclassificationboosting.R
@@ -40,7 +40,7 @@ options$noOfFolds <- 5
 options$deviancePlot <- TRUE
 options$outOfBagImprovementPlot <- TRUE
 options$relativeInfluencePlot <- TRUE
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
                            "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
                            "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlclassificationknn.R b/tests/testthat/test-mlclassificationknn.R
index f684e420..a41594d3 100644
--- a/tests/testthat/test-mlclassificationknn.R
+++ b/tests/testthat/test-mlclassificationknn.R
@@ -38,7 +38,7 @@ options$modelValid <- "validationManual"
 options$noOfFolds <- 5
 options$errorVsKPlot <- TRUE
 options$weightsPlot <- TRUE
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
                            "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
                            "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlclassificationlda.R b/tests/testthat/test-mlclassificationlda.R
index 176bafc8..ec64f16a 100644
--- a/tests/testthat/test-mlclassificationlda.R
+++ b/tests/testthat/test-mlclassificationlda.R
@@ -19,7 +19,7 @@ options$modelOptimization <- "manual"
 options$modelValid <- "validationManual"
 options$multicolTable <- TRUE
 options$noOfFolds <- 5
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
                            "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
                            "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlclassificationrandomforest.R b/tests/testthat/test-mlclassificationrandomforest.R
index 2f182217..73a944f1 100644
--- a/tests/testthat/test-mlclassificationrandomforest.R
+++ b/tests/testthat/test-mlclassificationrandomforest.R
@@ -39,7 +39,7 @@ options$noOfFolds <- 5
 options$accuracyDecreasePlot <- TRUE
 options$purityIncreasePlot <- TRUE
 options$treesVsModelErrorPlot <- TRUE
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
                            "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
                            "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlclusteringdensitybased.R b/tests/testthat/test-mlclusteringdensitybased.R
index c26459a0..d1f9208e 100644
--- a/tests/testthat/test-mlclusteringdensitybased.R
+++ b/tests/testthat/test-mlclusteringdensitybased.R
@@ -9,7 +9,7 @@ options$distance <- "normalDensities"
 options[["kDistancePlot"]] <- TRUE
 options$modelOptimization <- "manual"
 options$tsneClusterPlot <- TRUE
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
                            "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
                            "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlclusteringfuzzycmeans.R b/tests/testthat/test-mlclusteringfuzzycmeans.R
index 802ea21f..98f19837 100644
--- a/tests/testthat/test-mlclusteringfuzzycmeans.R
+++ b/tests/testthat/test-mlclusteringfuzzycmeans.R
@@ -2,7 +2,7 @@ context("Machine Learning Fuzzy C-Means Clustering")
 
 # Test fixed model #############################################################
 options <- initMlOptions("mlClusteringFuzzyCMeans")
-options$predictors <- list("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
+options$predictors <- c("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
 options$predictors.types <- rep("scale", length(options$predictors))
 options$modelOptimization <- "manual"
 options$predictionsColumn <- ""
@@ -22,7 +22,7 @@ options$predictionsColumn <- ""
 options$validationMeasures <- TRUE
 options$modelOptimization <- "optimized"
 options$tsneClusterPlot <- TRUE
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
                            "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
                            "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlclusteringhierarchical.R b/tests/testthat/test-mlclusteringhierarchical.R
index 87c86d88..3583a0c6 100644
--- a/tests/testthat/test-mlclusteringhierarchical.R
+++ b/tests/testthat/test-mlclusteringhierarchical.R
@@ -2,7 +2,7 @@ context("Machine Learning Hierarchical Clustering")
 
 # Test fixed model #############################################################
 options <- initMlOptions("mlClusteringHierarchical")
-options$predictors <- list("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
+options$predictors <- c("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
 options$predictors.types <- rep("scale", length(options$predictors))
 options$modelOptimization <- "manual"
 options$predictionsColumn <- ""
@@ -23,7 +23,7 @@ options$validationMeasures <- TRUE
 options$dendrogram <- TRUE
 options$modelOptimization <- "optimized"
 options$tsneClusterPlot <- TRUE
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
                            "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
                            "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlclusteringkmeans.R b/tests/testthat/test-mlclusteringkmeans.R
index 1176b19a..fceb04db 100644
--- a/tests/testthat/test-mlclusteringkmeans.R
+++ b/tests/testthat/test-mlclusteringkmeans.R
@@ -2,7 +2,7 @@ context("Machine Learning K-Means Clustering")
 
 # Test fixed model #############################################################
 options <- initMlOptions("mlClusteringKMeans")
-options$predictors <- list("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
+options$predictors <- c("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
 options$predictors.types <- rep("scale", length(options$predictors))
 options$modelOptimization <- "manual"
 options$predictionsColumn <- ""
@@ -18,7 +18,7 @@ jaspTools::expect_equal_tables(table,
 
 # Test optimized model #########################################################
 options <- initMlOptions("mlClusteringKMeans")
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
     "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
     "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
@@ -104,7 +104,7 @@ test_that("t-SNE Cluster Plot matches", {
 context("Machine Learning K-Medians Clustering")
 
 options <- initMlOptions("mlClusteringKMeans")
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
     "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
     "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
@@ -186,7 +186,7 @@ test_that("Elbow Method Plot matches", {
 context("Machine Learning K-Medoids Clustering")
 
 options <- initMlOptions("mlClusteringKMeans")
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
     "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
     "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
@@ -198,6 +198,7 @@ options$validationMeasures <- TRUE
 options$elbowMethodPlot <- TRUE
 options$clusterMeanPlot <- TRUE
 options$centers <- "medoids"
+options$algorithm <- "clara"
 options$setSeed <- TRUE
 options$modelOptimization <- "optimized"
 options$addPredictions <- FALSE
diff --git a/tests/testthat/test-mlclusteringmodelbased.R b/tests/testthat/test-mlclusteringmodelbased.R
index 6358b63c..8db4e150 100644
--- a/tests/testthat/test-mlclusteringmodelbased.R
+++ b/tests/testthat/test-mlclusteringmodelbased.R
@@ -2,7 +2,7 @@ context("Machine Learning K-Means Clustering")
 
 # Test fixed model #############################################################
 options <- initMlOptions("mlClusteringModelBased")
-options$predictors <- list("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
+options$predictors <- c("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
 options$predictors.types <- rep("scale", length(options$predictors))
 options$modelOptimization <- "manual"
 options$predictionsColumn <- ""
@@ -17,7 +17,7 @@ jaspTools::expect_equal_tables(table,
 
 # Test optimized model #########################################################
 options <- initMlOptions("mlClusteringModelBased")
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
     "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
     "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlclusteringrandomforest.R b/tests/testthat/test-mlclusteringrandomforest.R
index 571775ec..121f649a 100644
--- a/tests/testthat/test-mlclusteringrandomforest.R
+++ b/tests/testthat/test-mlclusteringrandomforest.R
@@ -2,7 +2,7 @@ context("Machine Learning Random Forest Clustering")
 
 # Test fixed model #############################################################
 options <- initMlOptions("mlClusteringRandomForest")
-options$predictors <- list("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
+options$predictors <- c("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
 options$predictors.types <- rep("scale", length(options$predictors))
 options$modelOptimization <- "manual"
 options$predictionsColumn <- ""
@@ -35,7 +35,7 @@ options$validationMeasures <- TRUE
 options$featureImportanceTable <- TRUE
 options$modelOptimization <- "optimized"
 options$tsneClusterPlot <- TRUE
-options$predictors <- list("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
+options$predictors <- c("Alcohol", "Malic", "Ash", "Alcalinity", "Magnesium", "Phenols",
                            "Flavanoids", "Nonflavanoids", "Proanthocyanins", "Color",
                            "Hue", "Dilution", "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlregressionboosting.R b/tests/testthat/test-mlregressionboosting.R
index ab2e6ea0..71af7c50 100644
--- a/tests/testthat/test-mlregressionboosting.R
+++ b/tests/testthat/test-mlregressionboosting.R
@@ -49,7 +49,7 @@ options$deviancePlot <- TRUE
 options$outOfBagImprovementPlot <- TRUE
 options$relativeInfluencePlot <- TRUE
 options$predictedPerformancePlot <- TRUE
-options$predictors <- list("Malic", "Ash", "Alcalinity", "Magnesium", "Phenols", "Flavanoids",
+options$predictors <- c("Malic", "Ash", "Alcalinity", "Magnesium", "Phenols", "Flavanoids",
                            "Nonflavanoids", "Proanthocyanins", "Color", "Hue", "Dilution",
                            "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlregressionknn.R b/tests/testthat/test-mlregressionknn.R
index b61af0b4..e81bc8c0 100644
--- a/tests/testthat/test-mlregressionknn.R
+++ b/tests/testthat/test-mlregressionknn.R
@@ -46,7 +46,7 @@ options$modelValid <- "validationManual"
 options$noOfFolds <- 5
 options$errorVsKPlot <- TRUE
 options$predictedPerformancePlot <- TRUE
-options$predictors <- list("Malic", "Ash", "Alcalinity", "Magnesium", "Phenols", "Flavanoids",
+options$predictors <- c("Malic", "Ash", "Alcalinity", "Magnesium", "Phenols", "Flavanoids",
                            "Nonflavanoids", "Proanthocyanins", "Color", "Hue", "Dilution",
                            "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlregressionlinear.R b/tests/testthat/test-mlregressionlinear.R
index 9e909c05..148c7572 100644
--- a/tests/testthat/test-mlregressionlinear.R
+++ b/tests/testthat/test-mlregressionlinear.R
@@ -9,7 +9,7 @@ options$saveModel <- FALSE
 options$holdoutData <- "holdoutManual"
 options$modelOptimization <- "manual"
 options$predictedPerformancePlot <- TRUE
-options$predictors <- list("Petal.Width", "Sepal.Length", "Sepal.Width", "Species")
+options$predictors <- c("Petal.Width", "Sepal.Length", "Sepal.Width", "Species")
 options$predictors.types <- c("scale", "scale", "scale", "nominal")
 options$setSeed <- TRUE
 options$target <- "Petal.Length"
diff --git a/tests/testthat/test-mlregressionrandomforest.R b/tests/testthat/test-mlregressionrandomforest.R
index f6426c47..de7d4e13 100644
--- a/tests/testthat/test-mlregressionrandomforest.R
+++ b/tests/testthat/test-mlregressionrandomforest.R
@@ -48,7 +48,7 @@ options$accuracyDecreasePlot <- TRUE
 options$purityIncreasePlot <- TRUE
 options$treesVsModelErrorPlot <- TRUE
 options$predictedPerformancePlot <- TRUE
-options$predictors <- list("Malic", "Ash", "Alcalinity", "Magnesium", "Phenols", "Flavanoids",
+options$predictors <- c("Malic", "Ash", "Alcalinity", "Magnesium", "Phenols", "Flavanoids",
                            "Nonflavanoids", "Proanthocyanins", "Color", "Hue", "Dilution",
                            "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))
diff --git a/tests/testthat/test-mlregressionregularized.R b/tests/testthat/test-mlregressionregularized.R
index fc709fec..161992eb 100644
--- a/tests/testthat/test-mlregressionregularized.R
+++ b/tests/testthat/test-mlregressionregularized.R
@@ -35,7 +35,7 @@ options$modelOptimization <- "optMin"
 options$modelValid <- "validationManual"
 options$noOfFolds <- 5
 options$predictedPerformancePlot <- TRUE
-options$predictors <- list("Malic", "Ash", "Alcalinity", "Magnesium", "Phenols", "Flavanoids",
+options$predictors <- c("Malic", "Ash", "Alcalinity", "Magnesium", "Phenols", "Flavanoids",
                            "Nonflavanoids", "Proanthocyanins", "Color", "Hue", "Dilution",
                            "Proline")
 options$predictors.types <- rep("scale", length(options$predictors))