diff --git a/DESCRIPTION b/DESCRIPTION
index 1bb6852..906af18 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -30,7 +30,7 @@ Suggests:
     tinytest
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.0
 Collate: 
     'AllGenerics.R'
     'append.R'
@@ -47,10 +47,11 @@ Collate:
     'discard.R'
     'keep.R'
     'mathematics.R'
+    'palettes.R'
     'plot.R'
     'remove.R'
     'replace.R'
-    'scale.R'
     'statistics.R'
+    'transform.R'
     'utilities.R'
     'zzz.R'
diff --git a/R/AllGenerics.R b/R/AllGenerics.R
index 32d193b..16daf92 100644
--- a/R/AllGenerics.R
+++ b/R/AllGenerics.R
@@ -1,6 +1,6 @@
 # GENERIC METHODS
 
-# Data cleaning ================================================================
+# Data preparation =============================================================
 ## Count -----------------------------------------------------------------------
 #' Count Values Using a Predicate
 #'
@@ -18,7 +18,7 @@
 #' @example inst/examples/ex-count.R
 #' @author N. Frerebeau
 #' @docType methods
-#' @family data cleaning tools
+#' @family data preparation tools
 #' @aliases count-method
 setGeneric(
   name = "count",
@@ -39,7 +39,7 @@ setGeneric(
 #' @example inst/examples/ex-detect.R
 #' @author N. Frerebeau
 #' @docType methods
-#' @family data cleaning tools
+#' @family data preparation tools
 #' @aliases detect-method
 setGeneric(
   name = "detect",
@@ -56,7 +56,7 @@ setGeneric(
 #' @example inst/examples/ex-keep.R
 #' @author N. Frerebeau
 #' @docType methods
-#' @family data cleaning tools
+#' @family data preparation tools
 #' @aliases keep-method
 setGeneric(
   name = "keep",
@@ -87,7 +87,7 @@ setGeneric(
 #' @example inst/examples/ex-discard.R
 #' @author N. Frerebeau
 #' @docType methods
-#' @family data cleaning tools
+#' @family data preparation tools
 #' @aliases discard-method
 setGeneric(
   name = "discard",
@@ -123,7 +123,7 @@ setGeneric(
 #' @example inst/examples/ex-compact.R
 #' @author N. Frerebeau
 #' @docType methods
-#' @family data cleaning tools
+#' @family data preparation tools
 #' @aliases compact-method
 setGeneric(
   name = "compact",
@@ -144,8 +144,67 @@ setGeneric(
   def = function(x, ...) standardGeneric("compact_rows")
 )
 
-## Remove ----------------------------------------------------------------------
-### NA --------------------------------------------------------------------------
+## Assign ----------------------------------------------------------------------
+#' Assign a Specific Row/Column to the Column/Row Names
+#'
+#' @param x A [`data.frame`].
+#' @param row A length-one [`numeric`] vector specifying the row number that is
+#'  to become the column names.
+#' @param column A length-one [`numeric`] vector specifying the column number
+#'  that is to become the row names.
+#' @param remove A [`logical`] scalar: should the specified row/column be removed
+#'  after making it the column/row names?
+#' @param ... Currently not used.
+#' @example inst/examples/ex-assign.R
+#' @return A [`data.frame`].
+#' @author N. Frerebeau
+#' @docType methods
+#' @family data preparation tools
+#' @name assign
+#' @rdname assign
+NULL
+
+#' @rdname assign
+#' @aliases assign_colnames-method
+setGeneric(
+  name = "assign_colnames",
+  def = function(x, ...) standardGeneric("assign_colnames")
+)
+
+#' @rdname assign
+#' @aliases assign_rownames-method
+setGeneric(
+  name = "assign_rownames",
+  def = function(x, ...) standardGeneric("assign_rownames")
+)
+
+#' Convert Row Names to an Explicit Column
+#'
+#' @param x A [`data.frame`].
+#' @param after A length-one [`numeric`] vector specifying a subscript,
+#'  after which the row names are to be appended.
+#' @param var A [`character`] string giving the name of column to use for row
+#'  names.
+#' @param remove A [`logical`] scalar: should the row names be removed?
+#' @param ... Currently not used.
+#' @example inst/examples/ex-assign.R
+#' @return A [`data.frame`].
+#' @author N. Frerebeau
+#' @docType methods
+#' @family data preparation tools
+#' @name append
+#' @rdname append
+NULL
+
+#' @rdname append
+#' @aliases append_rownames-method
+setGeneric(
+  name = "append_rownames",
+  def = function(x, ...) standardGeneric("append_rownames")
+)
+
+# Data cleaning ================================================================
+## NA --------------------------------------------------------------------------
 #' Tools for Working With Missing Values
 #'
 #' @description
@@ -178,7 +237,7 @@ setGeneric(
   def = function(x, ...) standardGeneric("replace_NA")
 )
 
-### Inf -------------------------------------------------------------------------
+## Inf -------------------------------------------------------------------------
 #' Tools for Working With Infinite Values
 #'
 #' @description
@@ -211,7 +270,7 @@ setGeneric(
   def = function(x, ...) standardGeneric("replace_Inf")
 )
 
-### Zeros -----------------------------------------------------------------------
+## Zeros -----------------------------------------------------------------------
 #' Tools for Working With Zeros
 #'
 #' @description
@@ -244,7 +303,7 @@ setGeneric(
   def = function(x, ...) standardGeneric("replace_zero")
 )
 
-### Empty string ---------------------------------------------------------------
+## Empty string ----------------------------------------------------------------
 #' Tools for Working With Empty String
 #'
 #' @description
@@ -277,7 +336,7 @@ setGeneric(
   def = function(x, ...) standardGeneric("replace_empty")
 )
 
-### Constant -------------------------------------------------------------------
+## Constant --------------------------------------------------------------------
 #' Remove Constant Columns
 #'
 #' @param x An \R object (should be a [`matrix`] or a [`data.frame`]).
@@ -297,65 +356,6 @@ setGeneric(
 )
 
 # Data transformation ==========================================================
-## Assign ----------------------------------------------------------------------
-#' Assign a Specific Row/Column to the Column/Row Names
-#'
-#'
-#' @param x A [`data.frame`].
-#' @param row A length-one [`numeric`] vector specifying the row number that is
-#'  to become the column names.
-#' @param column A length-one [`numeric`] vector specifying the column number
-#'  that is to become the row names.
-#' @param remove A [`logical`] scalar: should the specified row/column be removed
-#'  after making it the column/row names?
-#' @param ... Currently not used.
-#' @example inst/examples/ex-assign.R
-#' @return A [`data.frame`].
-#' @author N. Frerebeau
-#' @docType methods
-#' @family transformation tools
-#' @name assign
-#' @rdname assign
-NULL
-
-#' @rdname assign
-#' @aliases assign_colnames-method
-setGeneric(
-  name = "assign_colnames",
-  def = function(x, ...) standardGeneric("assign_colnames")
-)
-
-#' @rdname assign
-#' @aliases assign_rownames-method
-setGeneric(
-  name = "assign_rownames",
-  def = function(x, ...) standardGeneric("assign_rownames")
-)
-
-#' Convert Row Names to an Explicit Column
-#'
-#' @param x A [`data.frame`].
-#' @param after A length-one [`numeric`] vector specifying a subscript,
-#'  after which the row names are to be appended.
-#' @param var A [`character`] string giving the name of column to use for row
-#'  names.
-#' @param remove A [`logical`] scalar: should the row names be removed?
-#' @param ... Currently not used.
-#' @example inst/examples/ex-assign.R
-#' @return A [`data.frame`].
-#' @author N. Frerebeau
-#' @docType methods
-#' @family transformation tools
-#' @name append
-#' @rdname append
-NULL
-
-#' @rdname append
-#' @aliases append_rownames-method
-setGeneric(
-  name = "append_rownames",
-  def = function(x, ...) standardGeneric("append_rownames")
-)
 
 # Mathematics ==================================================================
 #' Least Common Multiple
@@ -506,6 +506,7 @@ setGeneric(
   def = function(object, ...) standardGeneric("confidence_multinomial")
 )
 
+# Resampling ===================================================================
 ## Bootstrap -------------------------------------------------------------------
 #' Bootstrap Estimation
 #'
diff --git a/R/scale.R b/R/palettes.R
similarity index 88%
rename from R/scale.R
rename to R/palettes.R
index 24f3fb7..774dd63 100644
--- a/R/scale.R
+++ b/R/palettes.R
@@ -1,19 +1,4 @@
-# SCALE
-NULL
-
-#' Rescale Continuous Vector
-#'
-#' Rescales continuous vector to have specified minimum and maximum.
-#' @param x A [`numeric`] vector.
-#' @param to A length-two [`numeric`] vector specifying the output range.
-#' @param from A length-two [`numeric`] vector specifying the input range.
-#' @note For internal use only.
-#' @return A [`numeric`] vector.
-#' @family scales
-#' @export
-scale_range <- function(x, to = c(0, 1), from = range(x, finite = TRUE)) {
-  (x - from[1L]) / diff(from) * diff(to) + to[1L]
-}
+# PALETTES
 
 #' Color Mapping
 #'
diff --git a/R/transform.R b/R/transform.R
new file mode 100644
index 0000000..9422ce3
--- /dev/null
+++ b/R/transform.R
@@ -0,0 +1,16 @@
+# DATA TRANSFORMATION
+NULL
+
+#' Rescale Continuous Vector
+#'
+#' Rescales continuous vector to have specified minimum and maximum.
+#' @param x A [`numeric`] vector.
+#' @param to A length-two [`numeric`] vector specifying the output range.
+#' @param from A length-two [`numeric`] vector specifying the input range.
+#' @note For internal use only.
+#' @return A [`numeric`] vector.
+#' @family data transformation tools
+#' @export
+scale_range <- function(x, to = c(0, 1), from = range(x, finite = TRUE)) {
+  (x - from[1L]) / diff(from) * diff(to) + to[1L]
+}
diff --git a/man/append.Rd b/man/append.Rd
index 39b5e4e..d94ddad 100644
--- a/man/append.Rd
+++ b/man/append.Rd
@@ -45,10 +45,15 @@ X <- data.frame(
 (Z <- append_rownames(Y))
 }
 \seealso{
-Other transformation tools: 
-\code{\link{assign}()}
+Other data preparation tools: 
+\code{\link{assign}()},
+\code{\link{compact}()},
+\code{\link{count}()},
+\code{\link{detect}()},
+\code{\link{discard}()},
+\code{\link{keep}()}
 }
 \author{
 N. Frerebeau
 }
-\concept{transformation tools}
+\concept{data preparation tools}
diff --git a/man/arkhe-package.Rd b/man/arkhe-package.Rd
index 16c6677..2360b55 100644
--- a/man/arkhe-package.Rd
+++ b/man/arkhe-package.Rd
@@ -3,7 +3,6 @@
 \docType{package}
 \name{arkhe-package}
 \alias{arkhe-package}
-\alias{_PACKAGE}
 \alias{arkhe}
 \title{arkhe: Tools for Cleaning Rectangular Data}
 \description{
diff --git a/man/assign.Rd b/man/assign.Rd
index 124ee46..3a537bb 100644
--- a/man/assign.Rd
+++ b/man/assign.Rd
@@ -53,10 +53,15 @@ X <- data.frame(
 (Z <- append_rownames(Y))
 }
 \seealso{
-Other transformation tools: 
-\code{\link{append}()}
+Other data preparation tools: 
+\code{\link{append}()},
+\code{\link{compact}()},
+\code{\link{count}()},
+\code{\link{detect}()},
+\code{\link{discard}()},
+\code{\link{keep}()}
 }
 \author{
 N. Frerebeau
 }
-\concept{transformation tools}
+\concept{data preparation tools}
diff --git a/man/compact.Rd b/man/compact.Rd
index 71c38d7..64fed59 100644
--- a/man/compact.Rd
+++ b/man/compact.Rd
@@ -57,18 +57,15 @@ compact(X, margin = 2)
 \seealso{
 \code{\link[=remove_NA]{remove_NA()}}, \code{\link[=remove_zero]{remove_zero()}}, \code{\link[=remove_empty]{remove_empty()}}
 
-Other data cleaning tools: 
+Other data preparation tools: 
+\code{\link{append}()},
+\code{\link{assign}()},
 \code{\link{count}()},
 \code{\link{detect}()},
 \code{\link{discard}()},
-\code{\link{empty}},
-\code{\link{infinite}},
-\code{\link{keep}()},
-\code{\link{missing}},
-\code{\link{remove_constant}()},
-\code{\link{zero}}
+\code{\link{keep}()}
 }
 \author{
 N. Frerebeau
 }
-\concept{data cleaning tools}
+\concept{data preparation tools}
diff --git a/man/count.Rd b/man/count.Rd
index 583b1da..39697bb 100644
--- a/man/count.Rd
+++ b/man/count.Rd
@@ -51,18 +51,15 @@ count(X, f = is.na, margin = 1)
 count(X, f = is.na, margin = 2, negate = TRUE)
 }
 \seealso{
-Other data cleaning tools: 
+Other data preparation tools: 
+\code{\link{append}()},
+\code{\link{assign}()},
 \code{\link{compact}()},
 \code{\link{detect}()},
 \code{\link{discard}()},
-\code{\link{empty}},
-\code{\link{infinite}},
-\code{\link{keep}()},
-\code{\link{missing}},
-\code{\link{remove_constant}()},
-\code{\link{zero}}
+\code{\link{keep}()}
 }
 \author{
 N. Frerebeau
 }
-\concept{data cleaning tools}
+\concept{data preparation tools}
diff --git a/man/detect.Rd b/man/detect.Rd
index f69deb1..61967ba 100644
--- a/man/detect.Rd
+++ b/man/detect.Rd
@@ -53,18 +53,15 @@ detect(X, f = is.na, margin = 1)
 detect(X, f = is.na, margin = 2, negate = TRUE, all = TRUE)
 }
 \seealso{
-Other data cleaning tools: 
+Other data preparation tools: 
+\code{\link{append}()},
+\code{\link{assign}()},
 \code{\link{compact}()},
 \code{\link{count}()},
 \code{\link{discard}()},
-\code{\link{empty}},
-\code{\link{infinite}},
-\code{\link{keep}()},
-\code{\link{missing}},
-\code{\link{remove_constant}()},
-\code{\link{zero}}
+\code{\link{keep}()}
 }
 \author{
 N. Frerebeau
 }
-\concept{data cleaning tools}
+\concept{data preparation tools}
diff --git a/man/discard.Rd b/man/discard.Rd
index f8e14fd..fc699d4 100644
--- a/man/discard.Rd
+++ b/man/discard.Rd
@@ -92,18 +92,15 @@ discard(X, f = is.na, margin = 1, all = FALSE)
 discard(X, f = is.na, margin = 2, all = FALSE)
 }
 \seealso{
-Other data cleaning tools: 
+Other data preparation tools: 
+\code{\link{append}()},
+\code{\link{assign}()},
 \code{\link{compact}()},
 \code{\link{count}()},
 \code{\link{detect}()},
-\code{\link{empty}},
-\code{\link{infinite}},
-\code{\link{keep}()},
-\code{\link{missing}},
-\code{\link{remove_constant}()},
-\code{\link{zero}}
+\code{\link{keep}()}
 }
 \author{
 N. Frerebeau
 }
-\concept{data cleaning tools}
+\concept{data preparation tools}
diff --git a/man/empty.Rd b/man/empty.Rd
index 913c47d..84bb5d3 100644
--- a/man/empty.Rd
+++ b/man/empty.Rd
@@ -63,12 +63,7 @@ replace_empty(X, value = "XXX")
 }
 \seealso{
 Other data cleaning tools: 
-\code{\link{compact}()},
-\code{\link{count}()},
-\code{\link{detect}()},
-\code{\link{discard}()},
 \code{\link{infinite}},
-\code{\link{keep}()},
 \code{\link{missing}},
 \code{\link{remove_constant}()},
 \code{\link{zero}}
diff --git a/man/infinite.Rd b/man/infinite.Rd
index 1958c7e..4ffcc70 100644
--- a/man/infinite.Rd
+++ b/man/infinite.Rd
@@ -63,12 +63,7 @@ replace_Inf(X, value = 0)
 }
 \seealso{
 Other data cleaning tools: 
-\code{\link{compact}()},
-\code{\link{count}()},
-\code{\link{detect}()},
-\code{\link{discard}()},
 \code{\link{empty}},
-\code{\link{keep}()},
 \code{\link{missing}},
 \code{\link{remove_constant}()},
 \code{\link{zero}}
diff --git a/man/keep.Rd b/man/keep.Rd
index edc7670..ebe4669 100644
--- a/man/keep.Rd
+++ b/man/keep.Rd
@@ -92,18 +92,15 @@ keep(X, f = is.na, margin = 1, negate = TRUE, all = TRUE)
 keep(X, f = is.na, margin = 2, negate = TRUE, all = TRUE)
 }
 \seealso{
-Other data cleaning tools: 
+Other data preparation tools: 
+\code{\link{append}()},
+\code{\link{assign}()},
 \code{\link{compact}()},
 \code{\link{count}()},
 \code{\link{detect}()},
-\code{\link{discard}()},
-\code{\link{empty}},
-\code{\link{infinite}},
-\code{\link{missing}},
-\code{\link{remove_constant}()},
-\code{\link{zero}}
+\code{\link{discard}()}
 }
 \author{
 N. Frerebeau
 }
-\concept{data cleaning tools}
+\concept{data preparation tools}
diff --git a/man/missing.Rd b/man/missing.Rd
index bdda2ce..7cdf33e 100644
--- a/man/missing.Rd
+++ b/man/missing.Rd
@@ -63,13 +63,8 @@ replace_NA(X, value = 0)
 }
 \seealso{
 Other data cleaning tools: 
-\code{\link{compact}()},
-\code{\link{count}()},
-\code{\link{detect}()},
-\code{\link{discard}()},
 \code{\link{empty}},
 \code{\link{infinite}},
-\code{\link{keep}()},
 \code{\link{remove_constant}()},
 \code{\link{zero}}
 }
diff --git a/man/palette_color.Rd b/man/palette_color.Rd
index d747f37..7691cf7 100644
--- a/man/palette_color.Rd
+++ b/man/palette_color.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/scale.R
+% Please edit documentation in R/palettes.R
 \name{palette_color}
 \alias{palette_color}
 \alias{palette_color_continuous}
diff --git a/man/palette_shape.Rd b/man/palette_shape.Rd
index 0202871..ad01594 100644
--- a/man/palette_shape.Rd
+++ b/man/palette_shape.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/scale.R
+% Please edit documentation in R/palettes.R
 \name{palette_shape}
 \alias{palette_shape}
 \title{Symbol Mapping}
diff --git a/man/palette_size.Rd b/man/palette_size.Rd
index 8e46b6d..0db7999 100644
--- a/man/palette_size.Rd
+++ b/man/palette_size.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/scale.R
+% Please edit documentation in R/palettes.R
 \name{palette_size}
 \alias{palette_size}
 \title{Symbol Size Mapping}
diff --git a/man/remove_constant.Rd b/man/remove_constant.Rd
index ee800b9..50cd81a 100644
--- a/man/remove_constant.Rd
+++ b/man/remove_constant.Rd
@@ -39,13 +39,8 @@ remove_constant(X, na.rm = TRUE)
 }
 \seealso{
 Other data cleaning tools: 
-\code{\link{compact}()},
-\code{\link{count}()},
-\code{\link{detect}()},
-\code{\link{discard}()},
 \code{\link{empty}},
 \code{\link{infinite}},
-\code{\link{keep}()},
 \code{\link{missing}},
 \code{\link{zero}}
 }
diff --git a/man/scale_range.Rd b/man/scale_range.Rd
index 035cec5..03138b9 100644
--- a/man/scale_range.Rd
+++ b/man/scale_range.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/scale.R
+% Please edit documentation in R/transform.R
 \name{scale_range}
 \alias{scale_range}
 \title{Rescale Continuous Vector}
@@ -22,4 +22,4 @@ Rescales continuous vector to have specified minimum and maximum.
 \note{
 For internal use only.
 }
-\concept{scales}
+\concept{data transformation tools}
diff --git a/man/zero.Rd b/man/zero.Rd
index fa25018..4f8e053 100644
--- a/man/zero.Rd
+++ b/man/zero.Rd
@@ -63,13 +63,8 @@ replace_zero(X, value = 1)
 }
 \seealso{
 Other data cleaning tools: 
-\code{\link{compact}()},
-\code{\link{count}()},
-\code{\link{detect}()},
-\code{\link{discard}()},
 \code{\link{empty}},
 \code{\link{infinite}},
-\code{\link{keep}()},
 \code{\link{missing}},
 \code{\link{remove_constant}()}
 }
diff --git a/pkgdown/_pkgdown.yml b/pkgdown/_pkgdown.yml
index 41221c4..15ca872 100644
--- a/pkgdown/_pkgdown.yml
+++ b/pkgdown/_pkgdown.yml
@@ -4,21 +4,15 @@ template:
   package: tekton
 
 reference:
-- title: Data cleaning
+- title: Data Preparation
+  contents:
+  - has_concept("data preparation tools")
+- title: Data Cleaning
   contents:
   - has_concept("data cleaning tools")
 - title: Data transformation
   contents:
-  - has_concept("transformation tools")
-- title: Scales
-  contents:
-  - has_concept("scales")
-- title: Predicates
-  contents:
-  - has_concept("predicates")
-- title: Validation
-  contents:
-  - has_concept("validation methods")
+  - has_concept("data transformation tools")
 - title: Statistics
   contents:
   - has_concept("summary statistics")
@@ -31,6 +25,12 @@ reference:
 - title: Palettes
   contents:
   - has_concept("palettes")
+- title: Predicates
+  contents:
+  - has_concept("predicates")
+- title: Validation
+  contents:
+  - has_concept("validation methods")
 - title: Utilities
   contents:
   - has_concept("utilities")