diff --git a/NAMESPACE b/NAMESPACE
index 3b4321c..cb7a24b 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -13,6 +13,7 @@ export(as_fitted_DAG)
 export(as_sem)
 export(classify_variables)
 export(dsem)
+export(dsem_control)
 export(fit_tmb)
 export(list_parameters)
 export(make_dsem_ram)
@@ -26,6 +27,7 @@ importFrom(TMB,sdreport)
 importFrom(TMB,summary.sdreport)
 importFrom(igraph,graph_from_data_frame)
 importFrom(igraph,plot.igraph)
+importFrom(methods,is)
 importFrom(sem,sem)
 importFrom(stats,"tsp<-")
 importFrom(stats,.preformat.ts)
diff --git a/R/dsem.R b/R/dsem.R
index 0cef552..d311129 100644
--- a/R/dsem.R
+++ b/R/dsem.R
@@ -13,16 +13,8 @@
 #' @param estimate_delta0 Boolean indicating whether to estimate deviations from equilibrium in initial year
 #'        as fixed effects, or alternatively to assume that dynamics start at some stochastic draw away from
 #'        the stationary distribution
-#' @param run_model Boolean indicating whether to estimate parameters (the default), or
-#'        instead to return the model inputs and compiled TMB object without running;
-#' @param quiet Boolean indicating whether to run model printing messages to terminal or not;
-#' @param use_REML Boolean indicating whether to treat non-variance fixed effects as random,
-#'        either to motigate bias in estimated variance parameters or improve efficiency for
-#'        parameter estimation given correlated fixed and random effects
-#' @param parameters list of fixed and random effects, e.g., as constructed by \code{dsem} and then modified
-#'        by hand (only helpful for advanced users to change starting values or restart at intended values)
-#' @param map list of fixed and mirrored parameters, constructed by \code{dsem} by default but available
-#'        to override this default and then pass to \code{\link[TMB]{MakeADFun}}
+#' @param control Output from \code{\link{dsem_control}}, used to define user
+#'        settings, and see documentation for that function for details.
 #' @param ... Additional parameters passed to \code{\link{fit_tmb}}
 #'
 #' @importFrom TMB compile dynlib MakeADFun sdreport summary.sdreport
@@ -30,6 +22,7 @@
 #' @importFrom Matrix solve Cholesky
 #' @importFrom sem sem
 #' @importFrom igraph plot.igraph graph_from_data_frame
+#' @importFrom methods is
 #'
 #' @details
 #' A DSEM involves (at a minimum):
@@ -106,8 +99,8 @@
 #' fit = dsem( sem=sem,
 #'             tsdata = tsdata,
 #'             newtonsteps = 0,
-#'             quiet = TRUE,
-#'             estimate_delta0 = TRUE )
+#'             estimate_delta0 = TRUE,
+#'             control = dsem_control(quiet=TRUE) )
 #' summary( fit )
 #' plot( fit )
 #' plot( fit, edge_label="value" )
@@ -119,18 +112,17 @@ function( sem,
           tsdata,
           family = rep("fixed",ncol(tsdata)),
           estimate_delta0 = FALSE,
-          quiet = FALSE,
-          run_model = TRUE,
-          use_REML = TRUE,
-          parameters = NULL,
-          map = NULL,
+          control = dsem_control(),
           ... ){
 
+  # General error checks
+  if( isFALSE(is(control, "dsem_control")) ) stop("`control` must be made by `dsem_control()`")
+
   # (I-Rho)^-1 * Gamma * (I-Rho)^-1
   out = make_dsem_ram( sem,
                   times = as.numeric(time(tsdata)),
                   variables = colnames(tsdata),
-                  quiet = quiet )
+                  quiet = control$quiet )
   ram = out$ram
 
   # Error checks
@@ -148,7 +140,7 @@ function( sem,
                "y_tj" = tsdata )
 
   # Construct parameters
-  if( is.null(parameters) ){
+  if( is.null(control$parameters) ){
     Params = list( "beta_z" = rep(0,max(ram[,4])),
                    "lnsigma_j" = rep(0,ncol(tsdata)),
                    "mu_j" = rep(0,ncol(tsdata)),
@@ -170,11 +162,11 @@ function( sem,
     start_z = tapply( as.numeric(ram[which_nonzero,5]), INDEX=ram[which_nonzero,4], mean )
     Params$beta_z = ifelse( is.na(start_z), Params$beta_z, start_z)
   }else{
-    Params = parameters
+    Params = control$parameters
   }
 
   # Construct map
-  if( is.null(map) ){
+  if( is.null(control$map) ){
     Map = list()
     Map$x_tj = factor(ifelse( is.na(as.vector(tsdata)) | (Data$familycode_j[col(tsdata)] %in% c(1,2,3,4)), seq_len(prod(dim(tsdata))), NA ))
     Map$lnsigma_j = factor( ifelse(Data$familycode_j==0, NA, seq_along(Params$lnsigma_j)) )
@@ -182,17 +174,17 @@ function( sem,
     # Map off mean for latent variables
     Map$mu_j = factor( ifelse(colSums(!is.na(tsdata))==0, NA, 1:ncol(tsdata)) )
   }else{
-    Map = map
+    Map = control$map
   }
 
   # Initial run
-  if(isTRUE(use_REML)){
+  if(isTRUE(control$use_REML)){
     Random = c( "x_tj", "mu_j" )
   }else{
     Random = "x_tj"
   }
   obj = MakeADFun( data=Data, parameters=Params, random=Random, map=Map, DLL="dsem" )
-  if(quiet==FALSE) list_parameters(obj)
+  if(control$quiet==FALSE) list_parameters(obj)
   out = list( "obj"=obj,
               "ram"=ram,
               "sem_full"=out$model,
@@ -200,15 +192,15 @@ function( sem,
               "call" = match.call() )
 
   # Export stuff
-  if( run_model==FALSE ){
+  if( control$run_model==FALSE ){
     return( out )
   }
 
   # Fit
   obj$env$beSilent()       # if(!is.null(Random))
   out$opt = fit_tmb( obj,
-                     quiet = quiet,
-                     control = list(eval.max=10000, iter.max=10000, trace=ifelse(quiet==TRUE,0,1) ),
+                     quiet = control$quiet,
+                     control = list(eval.max=10000, iter.max=10000, trace=ifelse(control$quiet==TRUE,0,1) ),
                      ... )
 
   # output
@@ -216,6 +208,45 @@ function( sem,
   return(out)
 }
 
+#' @title Detailed control for dsem structure
+#'
+#' @description Define a list of control parameters.  Note that
+#' the format of this input is likely to change more rapidly than that of
+#' \code{\link{dsem}}
+#'
+#' @param run_model Boolean indicating whether to estimate parameters (the default), or
+#'        instead to return the model inputs and compiled TMB object without running;
+#' @param quiet Boolean indicating whether to run model printing messages to terminal or not;
+#' @param use_REML Boolean indicating whether to treat non-variance fixed effects as random,
+#'        either to motigate bias in estimated variance parameters or improve efficiency for
+#'        parameter estimation given correlated fixed and random effects
+#' @param parameters list of fixed and random effects, e.g., as constructed by \code{dsem} and then modified
+#'        by hand (only helpful for advanced users to change starting values or restart at intended values)
+#' @param map list of fixed and mirrored parameters, constructed by \code{dsem} by default but available
+#'        to override this default and then pass to \code{\link[TMB]{MakeADFun}}
+#'
+#' @return
+#' An S3 object of class "dsem_control" that specifies detailed model settings,
+#' allowing user specification while also specifying default values
+#'
+#' @export
+dsem_control <-
+function( quiet = FALSE,
+          run_model = TRUE,
+          use_REML = TRUE,
+          parameters = NULL,
+          map = NULL ){
+
+  # Return
+  structure( list(
+    quiet = quiet,
+    run_model = run_model,
+    use_REML = use_REML,
+    parameters = parameters,
+    map = map
+  ), class = "dsem_control" )
+}
+
 #' @title summarize dsem
 #'
 #' @description summarize parameters from a fitted dynamic structural equation model
@@ -636,6 +667,9 @@ function( object,
 #'
 #' @description Extract the (marginal) log-likelihood of a dsem model
 #'
+#' @param object Output from \code{\link{dsem}}
+#' @param ... Not used
+#'
 #' @return object of class \code{logLik} with attributes
 #'   \item{val}{log-likelihood}
 #'   \item{df}{number of parameters}
diff --git a/man/dsem.Rd b/man/dsem.Rd
index 2bb6309..2eeefb6 100644
--- a/man/dsem.Rd
+++ b/man/dsem.Rd
@@ -9,11 +9,7 @@ dsem(
   tsdata,
   family = rep("fixed", ncol(tsdata)),
   estimate_delta0 = FALSE,
-  quiet = FALSE,
-  run_model = TRUE,
-  use_REML = TRUE,
-  parameters = NULL,
-  map = NULL,
+  control = dsem_control(),
   ...
 )
 }
@@ -33,20 +29,8 @@ Other options correspond to different specifications of measurement error.}
 as fixed effects, or alternatively to assume that dynamics start at some stochastic draw away from
 the stationary distribution}
 
-\item{quiet}{Boolean indicating whether to run model printing messages to terminal or not;}
-
-\item{run_model}{Boolean indicating whether to estimate parameters (the default), or
-instead to return the model inputs and compiled TMB object without running;}
-
-\item{use_REML}{Boolean indicating whether to treat non-variance fixed effects as random,
-either to motigate bias in estimated variance parameters or improve efficiency for
-parameter estimation given correlated fixed and random effects}
-
-\item{parameters}{list of fixed and random effects, e.g., as constructed by \code{dsem} and then modified
-by hand (only helpful for advanced users to change starting values or restart at intended values)}
-
-\item{map}{list of fixed and mirrored parameters, constructed by \code{dsem} by default but available
-to override this default and then pass to \code{\link[TMB]{MakeADFun}}}
+\item{control}{Output from \code{\link{dsem_control}}, used to define user
+settings, and see documentation for that function for details.}
 
 \item{...}{Additional parameters passed to \code{\link{fit_tmb}}}
 }
@@ -119,8 +103,8 @@ tsdata = TS[,c("time","gnp","pwage","cprofits",'consumption',
 fit = dsem( sem=sem,
             tsdata = tsdata,
             newtonsteps = 0,
-            quiet = TRUE,
-            estimate_delta0 = TRUE )
+            estimate_delta0 = TRUE,
+            control = dsem_control(quiet=TRUE) )
 summary( fit )
 plot( fit )
 plot( fit, edge_label="value" )
diff --git a/man/dsem_control.Rd b/man/dsem_control.Rd
new file mode 100644
index 0000000..46c583c
--- /dev/null
+++ b/man/dsem_control.Rd
@@ -0,0 +1,39 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/dsem.R
+\name{dsem_control}
+\alias{dsem_control}
+\title{Detailed control for dsem structure}
+\usage{
+dsem_control(
+  quiet = FALSE,
+  run_model = TRUE,
+  use_REML = TRUE,
+  parameters = NULL,
+  map = NULL
+)
+}
+\arguments{
+\item{quiet}{Boolean indicating whether to run model printing messages to terminal or not;}
+
+\item{run_model}{Boolean indicating whether to estimate parameters (the default), or
+instead to return the model inputs and compiled TMB object without running;}
+
+\item{use_REML}{Boolean indicating whether to treat non-variance fixed effects as random,
+either to motigate bias in estimated variance parameters or improve efficiency for
+parameter estimation given correlated fixed and random effects}
+
+\item{parameters}{list of fixed and random effects, e.g., as constructed by \code{dsem} and then modified
+by hand (only helpful for advanced users to change starting values or restart at intended values)}
+
+\item{map}{list of fixed and mirrored parameters, constructed by \code{dsem} by default but available
+to override this default and then pass to \code{\link[TMB]{MakeADFun}}}
+}
+\value{
+An S3 object of class "dsem_control" that specifies detailed model settings,
+allowing user specification while also specifying default values
+}
+\description{
+Define a list of control parameters.  Note that
+the format of this input is likely to change more rapidly than that of
+\code{\link{dsem}}
+}
diff --git a/man/logLik.dsem.Rd b/man/logLik.dsem.Rd
index 24d8bff..58a320c 100644
--- a/man/logLik.dsem.Rd
+++ b/man/logLik.dsem.Rd
@@ -6,6 +6,11 @@
 \usage{
 \method{logLik}{dsem}(object, ...)
 }
+\arguments{
+\item{object}{Output from \code{\link{dsem}}}
+
+\item{...}{Not used}
+}
 \value{
 object of class \code{logLik} with attributes
   \item{val}{log-likelihood}
diff --git a/vignettes/vignette.Rmd b/vignettes/vignette.Rmd
index 0d604e2..bf547de 100644
--- a/vignettes/vignette.Rmd
+++ b/vignettes/vignette.Rmd
@@ -65,8 +65,8 @@ tsdata = TS[,c("time","gnp","pwage","cprofits",'consumption',
 fit = dsem( sem=sem,
             tsdata = tsdata,
             newtonsteps = 0,
-            quiet = TRUE,
-            estimate_delta0 = TRUE )
+            estimate_delta0 = TRUE,
+            control = dsem_control(quiet = TRUE) )
 
 # Compile
 m1 = rbind( summary(fm_cons)$coef[-1,],
@@ -159,11 +159,17 @@ sem = "
   moose -> moose, 1, arM
 "
 # initial first without delta0 (to improve starting values)
-fit0 = dsem( sem=sem, tsdata=data, estimate_delta0=FALSE,
-            quiet=TRUE, getsd=FALSE )
+fit0 = dsem( sem = sem,
+             tsdata = data,
+             estimate_delta0 = FALSE,
+             control = dsem_control(quiet=TRUE),
+             getsd=FALSE )
 # Refit with delta0
-fit = dsem( sem=sem, tsdata=data, estimate_delta0=TRUE,
-            quiet=TRUE, parameters=fit0$obj$env$parList() )
+fit = dsem( sem = sem,
+            tsdata = data,
+            estimate_delta0 = TRUE,
+            control = dsem_control( quiet=TRUE,
+                                    parameters = fit0$obj$env$parList()) )
 
 # dynlm
 fm_wolf = dynlm( wolves ~ 1 + L(wolves) + L(moose), data=data )   #
@@ -263,7 +269,10 @@ sem = "
 "
 
 # Fit
-fit = dsem( sem=sem, tsdata=Z, family=family, use_REML=FALSE, quiet=TRUE )
+fit = dsem( sem = sem,
+            tsdata = Z,
+            family = family,
+            control = dsem_control(use_REML=FALSE, quiet=TRUE) )
 ParHat = fit$obj$env$parList()
 # summary( fit )
 
@@ -439,7 +448,9 @@ sem = "
 "
 
 # Fit model
-fit = dsem( sem=sem, tsdata=Z, use_REML=FALSE, quiet=TRUE )
+fit = dsem( sem = sem,
+            tsdata = Z,
+            control = dsem_control(use_REML=FALSE, quiet=TRUE) )
 # summary( fit )
 
 #
diff --git a/vignettes/vignette.pdf b/vignettes/vignette.pdf
index 5b0f694..52c51ec 100644
Binary files a/vignettes/vignette.pdf and b/vignettes/vignette.pdf differ