diff --git a/NAMESPACE b/NAMESPACE
index 62da194..0a6eb6e 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -13,8 +13,13 @@ S3method(set_var_labels,dataset)
 S3method(summary,dataset)
 S3method(tail,dataset)
 S3method(var_labels,dataset)
+S3method(xsd_convert,boolean)
+S3method(xsd_convert,character)
 S3method(xsd_convert,data.frame)
 S3method(xsd_convert,dataset)
+S3method(xsd_convert,factor)
+S3method(xsd_convert,integer)
+S3method(xsd_convert,numeric)
 S3method(xsd_convert,tibble)
 export("creator<-")
 export("dataset_title<-")
@@ -40,6 +45,7 @@ export(dataset_bibentry)
 export(dataset_download)
 export(dataset_title)
 export(dataset_to_triples)
+export(dataset_ttl_write)
 export(datasource_get)
 export(datasource_set)
 export(describe)
@@ -48,6 +54,7 @@ export(dublincore)
 export(geolocation)
 export(get_prefix)
 export(get_resource_identifier)
+export(id_to_column)
 export(identifier)
 export(is.dataset)
 export(language)
@@ -59,7 +66,6 @@ export(set_var_labels)
 export(size)
 export(subject)
 export(subject_create)
-export(ttl_dataset_write)
 export(var_labels)
 export(version)
 export(xsd_convert)
diff --git a/R/dataset.R b/R/dataset.R
index 4924295..f6ceda0 100644
--- a/R/dataset.R
+++ b/R/dataset.R
@@ -1,7 +1,7 @@
 #' @title Create a dataset
 #'
 #' @param x An R object that contains the data of the dataset (a data.frame or
-#' inherited from [`data.frame`][base::data.frame()], for example,
+#' inherited from [`data.frame`][base::data.frame()]), for example,
 #' [tibble::tibble()], [tsibble::tsibble()], [data.table::data.table()].
 #' @param author A single person or a vector of persons as authors, declared with
 #' \code{\link[utils:person]{person}}.
diff --git a/R/dataset_to_triples.R b/R/dataset_to_triples.R
index d17cf9f..7cf0bb8 100644
--- a/R/dataset_to_triples.R
+++ b/R/dataset_to_triples.R
@@ -2,43 +2,45 @@
 #' @description The dataset is converted into a three-column long format with
 #' columns \code{s} for subject, \code{p} for predicate and \code{o} for
 #' object.
-#' @param df A [data.frame] or similar object, or a [dataset].
+#' @param x An R object that contains the data of the dataset (a data.frame or
+#' inherited from [`data.frame`][base::data.frame()]), for example, [dataset()]
+#' [tibble::tibble()], [tsibble::tsibble()], [data.table::data.table()].
 #' @param idcol The identifier column. If \code{idcol} is \code{NULL} it attempts to
 #' use the \code{row.names(df)} as an \code{idcol}.
 #' @return The long form version of the original dataset, retaining the attributes
 #' and class.
 #' @export
 
-dataset_to_triples <- function(df, idcol=NULL) {
+dataset_to_triples <- function(x, idcol=NULL) {
 
-  is_dataset <- inherits(df, "dataset")
+  is_dataset <- inherits(x, "dataset")
 
   if (is_dataset) {
-    new_title = paste0(dataset_title(df), " [triple form]")
-    DataBibentry <- dataset_bibentry(df)
-    new_Subject <- subject(df)
+    new_title = paste0(dataset_title(x), " [triple form]")
+    DataBibentry <- dataset_bibentry(x)
+    new_Subject <- subject(x)
   }
 
   if (is.null(idcol)) {
-    df$new_id_col <- row.names(df)
-    idcol <- which(names(df)=="new_id_col" )
-    idcol_pos <- idcol_find(df, idcol)
-    seq_along_cols <- seq_along(df)[-idcol_pos]
+    x$new_id_col <- row.names(x)
+    idcol <- which(names(x)=="new_id_col" )
+    idcol_pos <- idcol_find(x, idcol)
+    seq_along_cols <- seq_along(x)[-idcol_pos]
   } else {
     ## See utils-idcol_find.R for the internal function
-    seq_along_cols <- seq_along(df)[-idcol_find(df, idcol)]
+    seq_along_cols <- seq_along(x)[-idcol_find(x, idcol)]
   }
 
-  triple_list <- lapply (seq_along_cols, function(x) {
-    data.frame(s = df[[idcol]],
-               p = names(df)[x],
-               o = df[[x]]
-    ) })
+  triple_list <- lapply (seq_along_cols, function(i) {
+    data.frame(s = x[[idcol]],
+               p = names(x)[i],
+               o = x[[i]])
+    })
 
   tmp <- do.call(rbind, triple_list)
 
   if (is_dataset) {
-    tmp2 <- dataset(x=tmp, author=creator(df), title = new_title)
+    tmp2 <- dataset(x=tmp, author=creator(x), title = new_title)
     tmp_DSD <- DataStructure(tmp2)
     tmp_DSD$s$label <- "Subject"
     tmp_DSD$s$label <- "Object"
diff --git a/R/id_to_column.R b/R/id_to_column.R
new file mode 100644
index 0000000..0e96a17
--- /dev/null
+++ b/R/id_to_column.R
@@ -0,0 +1,57 @@
+#' @title Add identifier to columns
+#'
+#' @description Add a prefixed identifier to the first column of the dataset.
+#' @inheritParams dataset
+#' @param prefix Defaults to \code{eg:} (example.com).
+#' @param ids Defaults to \code{NULL}.
+#' @return A dataset conforming the original sub-class of \code{x}.
+#' @examples
+#'
+#' # Example with a dataaset object:
+#' id_to_column(iris_dataset)
+#'
+#' # Example with a data.frame object:
+#'
+#' id_to_column(iris, prefix="eg:iris-o")
+#' @export
+id_to_column <- function(x, prefix = "eg:", ids = NULL) {
+
+  is_dataset <- is.dataset(x)
+
+  lastcol <- ncol(x)
+
+  if (is.null(ids)) {
+    ids <- gsub("[^[:alnum:]]", "-", row.names(x))
+  } else if (nrow(x)!=length(ids)) {
+    stop("id_to_column(x, ..., ids) : ids must be of same lengths as nrow(x).")
+  }
+
+  if (is.null(prefix)) { prefix <- "" }
+
+  rhs <- x
+  x$rowid <- paste0(prefix, ids)
+  lhs <- x[, "rowid", drop=FALSE]
+
+  if (is_dataset) {
+
+    DataBibentry <- dataset_bibentry(rhs)
+    tmp <- dataset(cbind(lhs, rhs),
+                   author=DataBibentry$author,
+                   title = DataBibentry$title)
+
+    if (nrow(tmp)>0) {
+      row.names(tmp) <- 1:nrow(tmp)
+    } else {
+      row.names(tmp) <- NULL
+    }
+
+    attr(tmp, "DataBibentry") <-  DataBibentry
+
+  } else {
+    tmp <- cbind(lhs, rhs)
+  }
+  tmp
+}
+
+
+
diff --git a/R/ttl_dataset_write.R b/R/ttl_dataset_write.R
index 6c60260..af8ae0f 100644
--- a/R/ttl_dataset_write.R
+++ b/R/ttl_dataset_write.R
@@ -16,12 +16,12 @@
 #'
 #' examplefile <- file.path(tempdir(), "ttl_dataset_write.ttl")
 #'
-#' ttl_dataset_write(tdf=testtdf, file_path = examplefile)
+#' dataset_ttl_write(tdf=testtdf, file_path = examplefile)
 #'
 #' readLines(examplefile)
 #' @export
 
-ttl_dataset_write <- function(tdf,
+dataset_ttl_write <- function(tdf,
                               ttl_namespace = NULL,
                               file_path = NULL,
                               overwrite = TRUE) {
@@ -30,7 +30,7 @@ ttl_dataset_write <- function(tdf,
   default_namespace <- getdata("dataset_namespace")
   default_namespace <- default_namespace[
     which(default_namespace$prefix %in% c("rdf:", "rdfs:", "owl:",
-                                          "qb:", "dcat:")),]
+                                          "qb:", "dcat:", "xsd:")),]
 
   ## validate dataset
   validate_tdf(tdf)
diff --git a/R/xsd_convert.R b/R/xsd_convert.R
index 382d5a4..17a07dd 100644
--- a/R/xsd_convert.R
+++ b/R/xsd_convert.R
@@ -24,7 +24,7 @@ xsd_convert.data.frame <- function(x, idcol=NULL, ...) {
 
     type <- switch(class(t)[[1]],
                    "numeric"   = "xs:decimal",
-                   "factor"    = "codelist",
+                   "factor"    = "xs:string",
                    "logical"   = "xs:boolean",
                    "integer"   = "xs:integer",
                    "Date"      = "xs:date",
@@ -90,28 +90,42 @@ xsd_convert.tibble <- function(x, idcol=NULL,...) {
   NextMethod()
 }
 
+#' @rdname xsd_convert
+#' @export
+#' @exportS3Method
 xsd_convert.character <- function(x, idcol=NULL, ...) {
   var_type <-  "xs:string"
   paste0('\"', x,  '\"', "^^<", var_type, ">")
 }
 
+#' @rdname xsd_convert
+#' @export
+#' @exportS3Method
 xsd_convert.numeric <- function(x, idcol=NULL, ...) {
   var_type <-  "xs:decimal"
   paste0('\"', as.character(x),  '\"', "^^<", var_type, ">")
 }
 
+#' @rdname xsd_convert
+#' @export
+#' @exportS3Method
 xsd_convert.integer <- function(x, idcol=NULL, ...) {
   var_type <-  "xs:integer"
   paste0('\"', as.character(x),  '\"', "^^<", var_type, ">")
 }
 
+#' @rdname xsd_convert
+#' @export
+#' @exportS3Method
 xsd_convert.boolean <- function(x, idcol=NULL, ...) {
   var_type <-  "xs:boolean"
   paste0('\"', as.character(x),  '\"', "^^<", var_type, ">")
 }
 
+#' @rdname xsd_convert
+#' @export
+#' @exportS3Method
 xsd_convert.factor<- function(x, idcol=NULL, codelist=NULL ) {
-
   if (is.null(codelist)) {
     var_type <-  "xs:string"
     paste0('\"', x,  '\"', "^^<", var_type, ">")
diff --git a/_pkgdown.yml b/_pkgdown.yml
index 8e010ed..0349c7c 100644
--- a/_pkgdown.yml
+++ b/_pkgdown.yml
@@ -68,6 +68,7 @@ reference:
     contents:
       - dataset
       - subsetting
+      - id_to_column
       - head.dataset
       - dataset_bibentry
       - describe
@@ -113,7 +114,7 @@ reference:
       - xsd_convert
       - get_prefix
       - dataset_to_triples
-      - ttl_dataset_write
+      - dataset_ttl_write
   - title: "Reproducible research workflows"
     desc: >
       Improve reproducability with recording data lifecycle, processing history as
diff --git a/man/dataset.Rd b/man/dataset.Rd
index 3348524..4f7a98b 100644
--- a/man/dataset.Rd
+++ b/man/dataset.Rd
@@ -63,7 +63,7 @@ is.dataset(x)
 }
 \arguments{
 \item{x}{An R object that contains the data of the dataset (a data.frame or
-inherited from \code{\link[base:data.frame]{data.frame}}, for example,
+inherited from \code{\link[base:data.frame]{data.frame}}), for example,
 \code{\link[tibble:tibble]{tibble::tibble()}}, \code{\link[tsibble:tsibble]{tsibble::tsibble()}}, \code{\link[data.table:data.table]{data.table::data.table()}}.}
 
 \item{author}{A single person or a vector of persons as authors, declared with
diff --git a/man/dataset_to_triples.Rd b/man/dataset_to_triples.Rd
index 284383b..d476a35 100644
--- a/man/dataset_to_triples.Rd
+++ b/man/dataset_to_triples.Rd
@@ -4,10 +4,12 @@
 \alias{dataset_to_triples}
 \title{Dataset to triples (three columns)}
 \usage{
-dataset_to_triples(df, idcol = NULL)
+dataset_to_triples(x, idcol = NULL)
 }
 \arguments{
-\item{df}{A \link{data.frame} or similar object, or a \link{dataset}.}
+\item{x}{An R object that contains the data of the dataset (a data.frame or
+inherited from \code{\link[base:data.frame]{data.frame}}), for example, \code{\link[=dataset]{dataset()}}
+\code{\link[tibble:tibble]{tibble::tibble()}}, \code{\link[tsibble:tsibble]{tsibble::tsibble()}}, \code{\link[data.table:data.table]{data.table::data.table()}}.}
 
 \item{idcol}{The identifier column. If \code{idcol} is \code{NULL} it attempts to
 use the \code{row.names(df)} as an \code{idcol}.}
diff --git a/man/ttl_dataset_write.Rd b/man/dataset_ttl_write.Rd
similarity index 88%
rename from man/ttl_dataset_write.Rd
rename to man/dataset_ttl_write.Rd
index a145615..31d6f4c 100644
--- a/man/ttl_dataset_write.Rd
+++ b/man/dataset_ttl_write.Rd
@@ -1,10 +1,10 @@
 % Generated by roxygen2: do not edit by hand
 % Please edit documentation in R/ttl_dataset_write.R
-\name{ttl_dataset_write}
-\alias{ttl_dataset_write}
+\name{dataset_ttl_write}
+\alias{dataset_ttl_write}
 \title{Write a dataset into Turtle serialisation}
 \usage{
-ttl_dataset_write(
+dataset_ttl_write(
   tdf,
   ttl_namespace = NULL,
   file_path = NULL,
@@ -35,7 +35,7 @@ testtdf <- data.frame (s = c("eg:o1", "eg:01", "eg:02"),
 
 examplefile <- file.path(tempdir(), "ttl_dataset_write.ttl")
 
-ttl_dataset_write(tdf=testtdf, file_path = examplefile)
+dataset_ttl_write(tdf=testtdf, file_path = examplefile)
 
 readLines(examplefile)
 }
diff --git a/man/id_to_column.Rd b/man/id_to_column.Rd
new file mode 100644
index 0000000..9b278dc
--- /dev/null
+++ b/man/id_to_column.Rd
@@ -0,0 +1,32 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/id_to_column.R
+\name{id_to_column}
+\alias{id_to_column}
+\title{Add identifier to columns}
+\usage{
+id_to_column(x, prefix = "eg:", ids = NULL)
+}
+\arguments{
+\item{x}{An R object that contains the data of the dataset (a data.frame or
+inherited from \code{\link[base:data.frame]{data.frame}}), for example,
+\code{\link[tibble:tibble]{tibble::tibble()}}, \code{\link[tsibble:tsibble]{tsibble::tsibble()}}, \code{\link[data.table:data.table]{data.table::data.table()}}.}
+
+\item{prefix}{Defaults to \code{eg:} (example.com).}
+
+\item{ids}{Defaults to \code{NULL}.}
+}
+\value{
+A dataset conforming the original sub-class of \code{x}.
+}
+\description{
+Add a prefixed identifier to the first column of the dataset.
+}
+\examples{
+
+# Example with a dataaset object:
+id_to_column(iris_dataset)
+
+# Example with a data.frame object:
+
+id_to_column(iris, prefix="eg:iris-o")
+}
diff --git a/man/xsd_convert.Rd b/man/xsd_convert.Rd
index 521dd86..fb13db2 100644
--- a/man/xsd_convert.Rd
+++ b/man/xsd_convert.Rd
@@ -5,6 +5,11 @@
 \alias{xsd_convert.data.frame}
 \alias{xsd_convert.dataset}
 \alias{xsd_convert.tibble}
+\alias{xsd_convert.character}
+\alias{xsd_convert.numeric}
+\alias{xsd_convert.integer}
+\alias{xsd_convert.boolean}
+\alias{xsd_convert.factor}
 \title{Convert to XML Schema Definition (XSD) types}
 \usage{
 xsd_convert(x, idcol, ...)
@@ -14,10 +19,20 @@ xsd_convert(x, idcol, ...)
 \method{xsd_convert}{dataset}(x, idcol = NULL, ...)
 
 \method{xsd_convert}{tibble}(x, idcol = NULL, ...)
+
+\method{xsd_convert}{character}(x, idcol = NULL, ...)
+
+\method{xsd_convert}{numeric}(x, idcol = NULL, ...)
+
+\method{xsd_convert}{integer}(x, idcol = NULL, ...)
+
+\method{xsd_convert}{boolean}(x, idcol = NULL, ...)
+
+\method{xsd_convert}{factor}(x, idcol = NULL, codelist = NULL)
 }
 \arguments{
 \item{x}{An R object that contains the data of the dataset (a data.frame or
-inherited from \code{\link[base:data.frame]{data.frame}}, for example,
+inherited from \code{\link[base:data.frame]{data.frame}}), for example,
 \code{\link[tibble:tibble]{tibble::tibble()}}, \code{\link[tsibble:tsibble]{tsibble::tsibble()}}, \code{\link[data.table:data.table]{data.table::data.table()}}.}
 
 \item{idcol}{The name or position of the column that contains the row
diff --git a/tests/testthat/test-dataset_to_triples.R b/tests/testthat/test-dataset_to_triples.R
new file mode 100644
index 0000000..412b219
--- /dev/null
+++ b/tests/testthat/test-dataset_to_triples.R
@@ -0,0 +1,13 @@
+
+
+test_that("dataset_to_triples works()", {
+  expect_equal(class(dataset_to_triples(iris_dataset)), "data.frame")
+  expect_equal(ncol(dataset_to_triples(iris_dataset)), 3)
+  expect_equal(nrow(dataset_to_triples(head(iris_dataset, 3))), dim(head(iris_dataset, 3))[1]*dim(head(iris_dataset, 3))[2])
+})
+
+
+
+
+
+
diff --git a/tests/testthat/test-ttl_dataset_write.R b/tests/testthat/test-dataset_ttl_write.R
similarity index 64%
rename from tests/testthat/test-ttl_dataset_write.R
rename to tests/testthat/test-dataset_ttl_write.R
index 250bc04..9a70b3d 100644
--- a/tests/testthat/test-ttl_dataset_write.R
+++ b/tests/testthat/test-dataset_ttl_write.R
@@ -1,14 +1,14 @@
-testfile <- file.path(tempdir(), "test-ttl_dataset_write.ttl")
+testfile <- file.path(tempdir(), "test-dataset_ttl_write.ttl")
 testtdf <- data.frame ( s = c("eg:o1", "eg:01", "eg:02"),
                         p = c("a", "eg-var:", "eg-var"),
                         o = c("qb:Observation", "\"1\"^^<xs:decimal>", "\"2\"^^<xs:decimal>") )
 
-ttl_dataset_write(tdf=testtdf,
+dataset_ttl_write(tdf=testtdf,
                   ttl_namespace = NULL,
                   file_path=testfile,
                   overwrite=TRUE)
 
-test_that("ttl_dataset_write() works:", {
+test_that("dataset_ttl_write() works:", {
   expect_true(file.exists(testfile))
   expect_true(grepl("@prefix  owl:", readLines(testfile)[1]))
   expect_equal(sum(
@@ -19,7 +19,7 @@ test_that("ttl_dataset_write() works:", {
 , 1)
 })
 
-test_that("ttl_dataset_write() validation works:", {
-  expect_error(ttl_dataset_write(tdf=iris, file = tempfile()))
-  expect_error(ttl_dataset_write(tdf=list(), file = tempfile()))
+test_that("dataset_ttl_write() validation works:", {
+  expect_error(dataset_ttl_write(tdf=iris, file = tempfile()))
+  expect_error(dataset_ttl_write(tdf=list(), file = tempfile()))
 })
diff --git a/tests/testthat/test-id_to_column.R b/tests/testthat/test-id_to_column.R
new file mode 100644
index 0000000..3d85664
--- /dev/null
+++ b/tests/testthat/test-id_to_column.R
@@ -0,0 +1,10 @@
+
+
+test_that("id_to_column works ()", {
+  expect_true(is.dataset(head(id_to_column(iris_dataset))))
+  expect_true(is.data.frame(head(id_to_column(iris))))
+  expect_equal(head(id_to_column(iris_dataset), 3)$rowid, paste0("eg:iris-o", 1:3))
+  expect_equal(head(id_to_column(x=iris, prefix="eg:iris-o" ), 3)$rowid, paste0("eg:iris-o", 1:3))
+})
+
+