diff --git a/DESCRIPTION b/DESCRIPTION
index a073924f..51d1ff67 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -24,7 +24,6 @@ LazyData: true
 Roxygen: list(markdown = TRUE)
 RoxygenNote: 7.2.2
 Imports:
-    dplyr,
     WeightIt,
     marginaleffects,
     tidyr,
diff --git a/R/assessBalance.R b/R/assessBalance.R
index e7f27895..2072373e 100644
--- a/R/assessBalance.R
+++ b/R/assessBalance.R
@@ -124,6 +124,9 @@ assessBalance <- function(home_dir, data, exposure, exposure_time_pts, outcome,
     if (missing(home_dir)) {
       stop("Please supply a home directory.", call. = FALSE)
     }
+    else if(!is.character(home_dir)){
+      stop("Please provide a valid home directory path as a string if you wish to save output locally.", call. = FALSE)
+    }
     else if(!dir.exists(home_dir)) {
       stop("Please provide a valid home directory path if you wish to save output locally.", call. = FALSE)
     }
@@ -133,24 +136,45 @@ assessBalance <- function(home_dir, data, exposure, exposure_time_pts, outcome,
     stop("Please supply data as either a dataframe with no missing data or imputed data in the form of a mids object or path to folder with imputed csv datasets.",
          call. = FALSE)
   }
+  else if (!mice::is.mids(data) & !is.data.frame(data) & !inherits(data, "list")) {
+    stop("Please provide wide data as a 'mids' object, a data frame, or a list of imputed csv files in the 'data' field.", call. = FALSE)
+  }
+
+
   if (missing(exposure)){
     stop("Please supply a single exposure.", call. = FALSE)
   }
+  else if(!is.character(exposure) | length(exposure) != 1){
+    stop("Please supply a single exposure as a character.", call. = FALSE)
+  }
+
   if (missing(outcome)){
     stop("Please supply a single outcome.", call. = FALSE)
   }
+  else if(!is.character(outcome) | length(outcome) != 1){
+    stop("Please supply a single outcome as a character.", call. = FALSE)
+  }
+
   if (missing(exposure_time_pts)){
     stop("Please supply the exposure time points at which you wish to create weights.", call. = FALSE)
   }
-
-  if (missing(type)){
-    stop("Please supply a 'weighted', 'prebalance' type", call. = FALSE)
+  else if(!is.numeric(exposure_time_pts)){
+    stop("Please supply a list of exposure time points as integers.", call. = FALSE)
   }
+
   if (missing(formulas)){
     stop("Please supply a list of balancing formulas.", call. = FALSE)
   }
+  else if(!inherits(formulas, "list")){
+    stop("Please provide a list of formulas for each exposure time point", call. = FALSE)
+  }
+  else if(length(formulas) != length(exposure_time_pts)){
+    stop("Please provide a list of formulas for each exposure time point", call. = FALSE)
+  }
 
-
+  if (missing(type)){
+    stop("Please supply a 'weighted', 'prebalance' type", call. = FALSE)
+  }
   if (!inherits(type, "character") | length(type) != 1 ){
     stop("Please provide a single type as a character string from the following list: 'prebalance', 'weighted'", call. = FALSE)
   }
@@ -164,10 +188,6 @@ assessBalance <- function(home_dir, data, exposure, exposure_time_pts, outcome,
     stop("The 'weighted' mode of this function requires weights be supplied in the form of output from createWeights.", call. = FALSE)
   }
 
-  if (!mice::is.mids(data) & !is.data.frame(data) & !inherits(data, "list")) {
-    stop("Please provide either a 'mids' object, a data frame, or a list of imputed csv files in the 'data' field.", call. = FALSE)
-  }
-
   if (!is.null(weights) & ! inherits(weights, "list")){
     stop("Please supply a list of weights output from the createWeights function.", call. = FALSE)
   }
@@ -186,8 +206,18 @@ assessBalance <- function(home_dir, data, exposure, exposure_time_pts, outcome,
     stop("Please provide a list variable names as characters that are important confounders.", call. = FALSE)
   }
 
-  if(!inherits(formulas, "list")){
-    stop("Please provide a list of formulas for each exposure time point", call. = FALSE)
+  if(!is.logical(verbose)){
+    stop("Please set verbose to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(verbose) != 1){
+    stop("Please provide a single TRUE or FALSE value to verbose.", call. = FALSE)
+  }
+
+  if(!is.logical(save.out)){
+    stop("Please set save.out to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(save.out) != 1){
+    stop("Please provide a single TRUE or FALSE value to save.out.", call. = FALSE)
   }
 
 
diff --git a/R/calcBalStats.R b/R/calcBalStats.R
index 27d34dae..d65c0268 100644
--- a/R/calcBalStats.R
+++ b/R/calcBalStats.R
@@ -5,22 +5,6 @@
 #' approaches to assessing balance for time-varying exposures by weighting
 #' statistics based on sample distribution in exposure histories.
 #'
-#' @importFrom ggplot2 ggplot
-#' @importFrom ggplot2 theme
-#' @importFrom ggplot2 geom_text
-#' @importFrom ggplot2 geom_vline
-#' @importFrom ggplot2 geom_point
-#' @importFrom ggplot2 xlab
-#' @importFrom ggplot2 aes
-#' @importFrom ggplot2 xlim
-#' @importFrom ggplot2 ggtitle
-#' @importFrom ggplot2 scale_y_discrete
-#' @importFrom ggplot2 element_text
-#' @importFrom ggplot2 element_rect
-#' @importFrom ggplot2 element_blank
-#' @importFrom ggplot2 guide_axis
-#' @importFrom ggplot2 ggsave
-#' @importFrom stargazer stargazer
 #' @param home_dir (optional) path to home directory (required if save.out =
 #'   TRUE)
 #' @param data data in wide format as: a data frame, path to folder of imputed
@@ -111,7 +95,6 @@ calcBalStats <- function(home_dir = NA, data, formulas, exposure, exposure_time_
   if (weighted == 1){
     weights_method = weights$method
     w <- weights$weights #IPTW weights
-    # data <- data %>% dplyr::mutate(weights = as.numeric(w))
     data$weights <- as.numeric(w)
   }
   else{
@@ -319,14 +302,6 @@ calcBalStats <- function(home_dir = NA, data, formulas, exposure, exposure_time_
 
             bal_stats <- as.data.frame(cbind(bal_stats, weighted_bal_stats))
 
-            # standardizing balance statistics after weighting by history
-            # bal_stats <- bal_stats %>%
-            #   dplyr::mutate(std_bal_stats = weighted_bal_stats /
-            #                   (sapply(seq(ncol(data[, covars])), function(x) { #issue: looking in data for unweighted vals but factors have additional vars
-            #                     sd(as.numeric(data[, covars][, x]), na.rm = TRUE) }) *# unweighted covar sd
-            #                      sd(data[, paste0(exposure, ".", exposure_time_pt)], na.rm = TRUE)))  # exposure SD at that time pt
-
-
             # bal_stats <- bal_stats %>%
             bal_stats$std_bal_stats <- weighted_bal_stats /
               (sapply(seq(nrow(bal_stats)), function(x) { #issue: looking in data for unweighted vals but factors have additional vars
@@ -501,10 +476,6 @@ calcBalStats <- function(home_dir = NA, data, formulas, exposure, exposure_time_
     bal_stats <- as.data.frame(bal_stats)
     bal_stats$covariate <- rownames(bal_stats)
 
-    # # Renames factor covariates
-    # bal_stats$covariate[sapply(strsplit(bal_stats$covariate, "_"), "[", 1) %in% factor_covariates] <-
-    #   sapply(strsplit(bal_stats$covariate, "_"), "[", 1)[sapply(strsplit(bal_stats$covariate, "_"), "[", 1) %in% factor_covariates]
-
     #averages across factor levels to create one bal stat per factor variable?
     data$ID <- as.numeric(data$ID)
     f_vars <- colnames(data)[sapply(data, is.factor)]
diff --git a/R/compareHistories.R b/R/compareHistories.R
index 09d60493..6628ec27 100644
--- a/R/compareHistories.R
+++ b/R/compareHistories.R
@@ -106,6 +106,9 @@ compareHistories <- function(home_dir, exposure, exposure_time_pts, outcome, mod
     if (missing(home_dir)) {
       stop("Please supply a home directory.", call. = FALSE)
     }
+    else if(!is.character(home_dir)){
+      stop("Please provide a valid home directory path as a string if you wish to save output locally.", call. = FALSE)
+    }
     else if(!dir.exists(home_dir)) {
       stop("Please provide a valid home directory path if you wish to save output locally.", call. = FALSE)
     }
@@ -114,20 +117,46 @@ compareHistories <- function(home_dir, exposure, exposure_time_pts, outcome, mod
   if (missing(exposure)){
     stop("Please supply a single exposure.", call. = FALSE)
   }
+  else if(!is.character(exposure) | length(exposure) != 1){
+    stop("Please supply a single exposure as a character.", call. = FALSE)
+  }
+
   if (missing(outcome)){
     stop("Please supply a single outcome.", call. = FALSE)
   }
+  else if(!is.character(outcome) | length(outcome) != 1){
+    stop("Please supply a single outcome as a character.", call. = FALSE)
+  }
+
   if (missing(exposure_time_pts)){
     stop("Please supply the exposure time points at which you wish to create weights.", call. = FALSE)
   }
+  else if(!is.numeric(exposure_time_pts)){
+    stop("Please supply a list of exposure time points as integers.", call. = FALSE)
+  }
 
   if (missing(model)){
     stop("Please supply a list of model output", call. = FALSE)
   }
-  if(!inherits(model, "list")){
+  else if(!inherits(model, "list")){
     stop("Please provide a list of model output from the fitModel function.", call. = FALSE)
   }
 
+  if(!is.logical(verbose)){
+    stop("Please set verbose to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(verbose) != 1){
+    stop("Please provide a single TRUE or FALSE value to verbose.", call. = FALSE)
+  }
+
+  if(!is.logical(save.out)){
+    stop("Please set save.out to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(save.out) != 1){
+    stop("Please provide a single TRUE or FALSE value to save.out.", call. = FALSE)
+  }
+
+
 
   if(save.out){
     histories_dir <- file.path(home_dir, "histories")
diff --git a/R/createFormulas.R b/R/createFormulas.R
index e7042cf8..23e2be1c 100644
--- a/R/createFormulas.R
+++ b/R/createFormulas.R
@@ -95,6 +95,9 @@ createFormulas <- function(home_dir, exposure, exposure_time_pts, outcome, type,
     if (missing(home_dir)) {
       stop("Please supply a home directory.", call. = FALSE)
     }
+    else if(!is.character(home_dir)){
+      stop("Please provide a valid home directory path as a string if you wish to save output locally.", call. = FALSE)
+    }
     else if(!dir.exists(home_dir)) {
       stop("Please provide a valid home directory path if you wish to save output locally.", call. = FALSE)
     }
@@ -103,20 +106,37 @@ createFormulas <- function(home_dir, exposure, exposure_time_pts, outcome, type,
   if (missing(exposure)){
     stop("Please supply a single exposure.", call. = FALSE)
   }
+  else if(!is.character(exposure) | length(exposure) != 1){
+    stop("Please supply a single exposure as a character.", call. = FALSE)
+  }
+
   if (missing(outcome)){
     stop("Please supply a single outcome.", call. = FALSE)
   }
+  else if(!is.character(outcome) | length(outcome) != 1){
+    stop("Please supply a single outcome as a character.", call. = FALSE)
+  }
+
   if (missing(exposure_time_pts)){
     stop("Please supply the exposure time points at which you wish to create weights.", call. = FALSE)
   }
+  else if(!is.numeric(exposure_time_pts)){
+    stop("Please supply a list of exposure time points as integers.", call. = FALSE)
+  }
+
   if (missing(tv_confounders)){
     warning("You have not specified any time-varying confounders. If you have time-varying exposure, please list all wide exposure variables as tv_confounders.", call. = FALSE)
     tv_confounders <- character(0)
   }
+  else if(!is.character(tv_confounders)){
+    stop("Please provide a list of time-varying confounders as character strings.")
+  }
+
   if (missing(ti_confounders)){
     stop("You have not specified time invariant confounders.", call. = FALSE)
     # ti_confounders <- NULL
   }
+
   if (missing(type)){
     stop("Please supply a 'full', 'short', or 'update' type", call. = FALSE)
   }
@@ -135,6 +155,20 @@ createFormulas <- function(home_dir, exposure, exposure_time_pts, outcome, type,
     stop("Please provide a data frame of balance statistics from the assessBalance function.", call. = FALSE)
   }
 
+  if(!is.logical(verbose)){
+    stop("Please set verbose to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(verbose) != 1){
+    stop("Please provide a single TRUE or FALSE value to verbose.", call. = FALSE)
+  }
+
+  if(!is.logical(save.out)){
+    stop("Please set save.out to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(save.out) != 1){
+    stop("Please provide a single TRUE or FALSE value to save.out.", call. = FALSE)
+  }
+
 
   time_varying_covariates <- tv_confounders
   all_covars <- c(tv_confounders, ti_confounders)
@@ -192,7 +226,11 @@ createFormulas <- function(home_dir, exposure, exposure_time_pts, outcome, type,
 
       else if (type == "update"){
         if(is.null(bal_stats)){
-          stop("Please provide balance statistics if you wish to run the update version of this function", call. = FALSE)
+          stop("Please provide balance statistics from the assessBalance() function if you wish to run the update version of this function", call. = FALSE)
+        }
+        else if (!is.data.frame(bal_stats)){
+          stop("Please provide balance statistics from the assessBalance() function if you wish to run the update version of this function", call. = FALSE)
+
         }
 
         if(verbose){
diff --git a/R/createWeights.R b/R/createWeights.R
index 0a109c07..888fd3c9 100644
--- a/R/createWeights.R
+++ b/R/createWeights.R
@@ -5,10 +5,6 @@
 #' relevant confounders.
 #'
 #' @export
-#' @importFrom ggplot2 ggplot
-#' @importFrom ggplot2 geom_histogram
-#' @importFrom ggplot2 ggsave
-#' @importFrom WeightIt weightitMSM
 #' @seealso {[WeightIt::weightitMSM()],
 #'   <https://ngreifer.github.io/WeightIt/reference/weightitMSM.html>}
 #' @param home_dir path to home directory (required if 'save.out' = TRUE)
@@ -71,6 +67,9 @@ createWeights <- function(home_dir, data, exposure, outcome, formulas, method =
     if (missing(home_dir)) {
       stop("Please supply a home directory.", call. = FALSE)
     }
+    else if(!is.character(home_dir)){
+      stop("Please provide a valid home directory path as a string if you wish to save output locally.", call. = FALSE)
+    }
     else if(!dir.exists(home_dir)) {
       stop("Please provide a valid home directory path if you wish to save output locally.", call. = FALSE)
     }
@@ -80,34 +79,56 @@ createWeights <- function(home_dir, data, exposure, outcome, formulas, method =
     stop("Please supply data as either a dataframe with no missing data or imputed data in the form of a mids object or path to folder with imputed csv datasets.",
          call. = FALSE)
   }
+  else if (!mice::is.mids(data) & !is.data.frame(data) & !inherits(data, "list")) {
+    stop("Please provide either a 'mids' object, a data frame, or a list of imputed data frames in the 'data' field.",
+         call. = FALSE)
+  }
+
   if (missing(exposure)){
     stop("Please supply a single exposure.", call. = FALSE)
   }
+  else if(!is.character(exposure) | length(exposure) != 1){
+    stop("Please supply a single exposure as a character.", call. = FALSE)
+  }
+
   if (missing(outcome)){
     stop("Please supply a single outcome.", call. = FALSE)
   }
+  else if(!is.character(outcome) | length(outcome) != 1){
+    stop("Please supply a single outcome as a character.", call. = FALSE)
+  }
 
   if (missing(formulas)){
     stop("Please supply a list of balancing formulas.", call. = FALSE)
   }
+  else if(!inherits(formulas, "list")){
+    stop("Please provide a list of formulas for each exposure time point", call. = FALSE)
+  }
 
   if(!inherits(method, "character")){
     stop("Please provide as a character string a weights method from this list: 'ps', 'glm', 'gbm', 'bart', 'super', 'cbps'.",
          call. = FALSE)
   }
-  if(! method %in% c("ps", "glm", "gbm", "bart", "super", "cbps")){
+  else if(! method %in% c("ps", "glm", "gbm", "bart", "super", "cbps")){
     stop("Please provide a weights method from this list: 'ps', 'glm', 'gbm', 'bart', 'super', 'cbps'.",
          call. = FALSE)
   }
 
-  if (!mice::is.mids(data) & !is.data.frame(data) & !inherits(data, "list")) {
-    stop("Please provide either a 'mids' object, a data frame, or a list of imputed data frames in the 'data' field.",
-         call. = FALSE)
+  if(!is.logical(verbose)){
+    stop("Please set verbose to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(verbose) != 1){
+    stop("Please provide a single TRUE or FALSE value to verbose.", call. = FALSE)
   }
 
-  if(!inherits(formulas, "list")){
-    stop("Please provide a list of formulas for each exposure time point", call. = FALSE)
+  if(!is.logical(save.out)){
+    stop("Please set save.out to either TRUE or FALSE.", call. = FALSE)
   }
+  else if(length(save.out) != 1){
+    stop("Please provide a single TRUE or FALSE value to save.out.", call. = FALSE)
+  }
+
+
 
   weights_method <- method
   form_name <- sapply(strsplit(names(formulas[1]), "_form"), "[", 1)
@@ -249,9 +270,9 @@ createWeights <- function(home_dir, data, exposure, outcome, formulas, method =
 
         if (verbose){
           cat(paste0("For imputation", i, " and ", weights_method,
-                         ", weighting method, the median weight value is ", round(median(fit$weights), 2) ,
-                         " (SD= ", round(sd(fit$weights), 2), "; range= ", round(min(fit$weights), 2), "-",
-                         round(max(fit$weights), 2), ")."), "\n")
+                     ", weighting method, the median weight value is ", round(median(fit$weights), 2) ,
+                     " (SD= ", round(sd(fit$weights), 2), "; range= ", round(min(fit$weights), 2), "-",
+                     round(max(fit$weights), 2), ")."), "\n")
           cat('\n')
         }
 
@@ -305,8 +326,8 @@ createWeights <- function(home_dir, data, exposure, outcome, formulas, method =
 
       if (verbose){
         cat(paste0("For the ", weights_method, " weighting method, the median weight value is ",
-                       round(median(data$weights), 2) , " (SD = ", round(sd(data$weights), 2), "; range = ",
-                       round(min(data$weights), 2), "-", round(max(data$weights), 2), ")."), "\n")
+                   round(median(data$weights), 2) , " (SD = ", round(sd(data$weights), 2), "; range = ",
+                   round(min(data$weights), 2), "-", round(max(data$weights), 2), ")."), "\n")
         cat('\n')
       }
 
diff --git a/R/fitModel.R b/R/fitModel.R
index 27abfe9e..17f50b56 100644
--- a/R/fitModel.R
+++ b/R/fitModel.R
@@ -109,6 +109,9 @@ fitModel <- function(home_dir, data, weights, exposure, exposure_time_pts, outco
     if (missing(home_dir)) {
       stop("Please supply a home directory.", call. = FALSE)
     }
+    else if(!is.character(home_dir)){
+      stop("Please provide a valid home directory path as a string if you wish to save output locally.", call. = FALSE)
+    }
     else if(!dir.exists(home_dir)) {
       stop("Please provide a valid home directory path if you wish to save output locally.", call. = FALSE)
     }
@@ -118,27 +121,43 @@ fitModel <- function(home_dir, data, weights, exposure, exposure_time_pts, outco
     stop("Please supply data as either a dataframe with no missing data or imputed data in the form of a mids object or path to folder with imputed csv datasets.",
          call. = FALSE)
   }
+  else if (!mice::is.mids(data) & !is.data.frame(data) & !inherits(data, "list")) {
+    stop("Please provide either a 'mids' object, a data frame, or a list of imputed data frames in the 'data' field.", call. = FALSE)
+  }
+
   if (missing(exposure)){
     stop("Please supply a single exposure.", call. = FALSE)
   }
+  else if(!is.character(exposure) | length(exposure) != 1){
+    stop("Please supply a single exposure as a character.", call. = FALSE)
+  }
+
   if (missing(outcome)){
     stop("Please supply a single outcome.", call. = FALSE)
   }
+  else if(!is.character(outcome) | length(outcome) != 1){
+    stop("Please supply a single outcome as a character.", call. = FALSE)
+  }
+
   if (missing(weights)){
     stop("Please supply a list of IPTW weights.", call. = FALSE)
   }
+  else if (!inherits(weights, "list")){
+    stop("Please supply a list of weights output from the createWeights function.", call. = FALSE)
+  }
+
   if (missing(exposure_time_pts)){
     stop("Please supply the exposure time points at which you wish to create weights.", call. = FALSE)
   }
+  else if(!is.numeric(exposure_time_pts)){
+    stop("Please supply a list of exposure time points as integers.", call. = FALSE)
+  }
+
   if (missing(model)){
     stop('Please provide an outcome model selection "m" from 0-3 (e.g., "m1")', call. = FALSE)
   }
-  if (!mice::is.mids(data) & !is.data.frame(data) & !inherits(data, "list")) {
-    stop("Please provide either a 'mids' object, a data frame, or a list of imputed data frames in the 'data' field.", call. = FALSE)
-  }
-
-  if (!is.character(model)){
-    stop('Please provide as a character string a valid model "m" from 0-3 (e.g., "m1")', call. = FALSE)
+  else if (!is.character(model) | length(model) != 1){
+    stop('Please provide a single outcome model selection "m" from 0-3 (e.g., "m1")', call. = FALSE)
   }
   if (!(model %in% c("m0", "m1", "m2", "m3"))) {
     stop('Please provide a valid model "m" from 0-3 (e.g., "m1")', call. = FALSE)
@@ -153,16 +172,38 @@ fitModel <- function(home_dir, data, weights, exposure, exposure_time_pts, outco
   if(!inherits(family, "function")){
     stop("Please provide a valid family in the form of a function (without quotations).", call. = FALSE)
   }
+  if(length(family) != 1){
+    stop("Please provide a single valid family in the form of a function (without quotations).", call. = FALSE)
+  }
+
   if(!inherits(link, "character")){
     stop("Please provide as a character a valid link function.", call. = FALSE)
   }
+  else if(length(link) != 1){
+    stop("Please provide as a character a valid link function.", call. = FALSE)
+  }
+
   if (!is.null(covariates)){
+    if(!is.character(covariates)){
+      stop("Please provide a list of character strings for covariates.", call. = FALSE)
+    }
     if (sum(as.numeric(sapply(strsplit(covariates, "\\."), "[", 2)) > exposure_time_pts[1], na.rm = T) > 0){
       warning("Please only include covariates that are time invariant or measured at the first exposure time point.")
     }
   }
-  if (!inherits(weights, "list")){
-    stop("Please supply a list of weights output from the createWeights function.", call. = FALSE)
+
+  if(!is.logical(verbose)){
+    stop("Please set verbose to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(verbose) != 1){
+    stop("Please provide a single TRUE or FALSE value to verbose.", call. = FALSE)
+  }
+
+  if(!is.logical(save.out)){
+    stop("Please set save.out to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(save.out) != 1){
+    stop("Please provide a single TRUE or FALSE value to save.out.", call. = FALSE)
   }
 
 
diff --git a/R/trimWeights.R b/R/trimWeights.R
index 79906e9a..d3465f35 100644
--- a/R/trimWeights.R
+++ b/R/trimWeights.R
@@ -63,25 +63,57 @@ trimWeights <- function(home_dir, exposure, outcome, weights, quantile = 0.95, v
     if (missing(home_dir)) {
       stop("Please supply a home directory.", call. = FALSE)
     }
+    else if(!is.character(home_dir)){
+      stop("Please provide a valid home directory path as a string if you wish to save output locally.", call. = FALSE)
+    }
     else if(!dir.exists(home_dir)) {
       stop("Please provide a valid home directory path if you wish to save output locally.", call. = FALSE)
     }
   }
 
+  if (missing(exposure)){
+    stop("Please supply a single exposure.", call. = FALSE)
+  }
+  else if(!is.character(exposure) | length(exposure) != 1){
+    stop("Please supply a single exposure as a character.", call. = FALSE)
+  }
+
   if (missing(weights)){
     stop("Please supply a list of IPTW weights to trim.", call. = FALSE)
   }
+  else if (!inherits(weights, "list")){
+    stop("Please supply a list of weights output from the createWeights function.", call. = FALSE)
+  }
+
+  if (missing(outcome)){
+    stop("Please supply a single outcome.", call. = FALSE)
+  }
+  else if(!is.character(outcome) | length(outcome) != 1){
+    stop("Please supply a single outcome as a character.", call. = FALSE)
+  }
+
   if(!is.numeric(quantile)){
-    stop('Please sprovide a numeric quantile value between 0 and 1.', call. = FALSE)
+    stop('Please provide a numeric quantile value between 0 and 1.', call. = FALSE)
   }
   else if (quantile > 1 || quantile < 0) {
     stop('Please provide a quantile value between 0 and 1.', call. = FALSE)
   }
 
-  if (!inherits(weights, "list")){
-    stop("Please supply a list of weights output from the createWeights function.", call. = FALSE)
+  if(!is.logical(verbose)){
+    stop("Please set verbose to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(verbose) != 1){
+    stop("Please provide a single TRUE or FALSE value to verbose.", call. = FALSE)
   }
 
+  if(!is.logical(save.out)){
+    stop("Please set save.out to either TRUE or FALSE.", call. = FALSE)
+  }
+  else if(length(save.out) != 1){
+    stop("Please provide a single TRUE or FALSE value to save.out.", call. = FALSE)
+  }
+
+
   if(save.out){
     weights_dir <- file.path(home_dir, "weights")
     if (!dir.exists(weights_dir)) {