diff --git a/01_debugging_comfy.R b/01_debugging_comfy.R
deleted file mode 100644
index 2cba950..0000000
--- a/01_debugging_comfy.R
+++ /dev/null
@@ -1,30 +0,0 @@
-# Determine the bug when you run `get_climates()`
-# Hint: Use `traceback()` to find where it occurs, add breakpoints / `browser()` calls
-# Hint: look at the types of the data and make sure they are what the functions expect.
-
-library(tidyverse)
-
-# Separate, flatten, and trim values in the vector
-clean <- function(vec) {
-  values <- strsplit(vec, ",")
-  flat_values <- unlist(values)
-  trimmed_values <- str_trim(flat_values)
-  trimmed_values
-}
-
-# Clean vector and get the unique values
-uniquify <- function(vec) {
-  clean_values <- clean(vec)
-  unique_values <- unique(clean_values)
-  unique_values
-}
-
-# Read data and get unique climate values
-get_climates <- function() {
-  planets <- read.csv2(here::here("activities/planets.csv"))
-  unique_climate <- uniquify(planets$climate)
-  unique_climate
-}
-
-# This example originally used in Amanda Gadrow's excellent debugging talk at rstudio::conf 2018,
-# https://github.com/ajmcoqui/debuggingRStudio/blob/b70a3575a3ff5e7867b05fb5e84568abba426c4b/error_example.R
diff --git a/01_debugging_jim.R b/01_debugging_jim.R
deleted file mode 100644
index c72f0b3..0000000
--- a/01_debugging_jim.R
+++ /dev/null
@@ -1,30 +0,0 @@
-# Determine the bug when you run `get_climates()`
-# Hint: Use `traceback()` to find where it occurs, add breakpoints / `browser()` calls
-# Hint: look at types of input
-
-library(tidyverse)
-
-# Separate, flatten, and trim values in the vector
-clean <- function(vec) {
-  values <- strsplit(vec, ",")
-  flat_values <- unlist(values)
-  trimmed_values <- str_trim(flat_values)
-  trimmed_values
-}
-
-# Clean vector and get the unique values
-uniquify <- function(vec) {
-  clean_values <- clean(vec)
-  unique_values <- unique(clean_values)
-  unique_values
-}
-
-# Read data and get unique climate values
-get_climates <- function() {
-  planets <- readr::read_csv2(here::here("activities/planets.csv"))
-  unique_climate <- uniquify(planets$climate)
-  unique_climate
-}
-
-# This example originally used in Amanda Gadrow's excellent debugging talk at rstudio::conf 2018,
-# https://github.com/ajmcoqui/debuggingRStudio/blob/b70a3575a3ff5e7867b05fb5e84568abba426c4b/error_example.R
diff --git a/01_debugging_spartan.R b/01_debugging_spartan.R
deleted file mode 100644
index 502adaa..0000000
--- a/01_debugging_spartan.R
+++ /dev/null
@@ -1,30 +0,0 @@
-# Determine the bug when you run `get_climates()`
-# Hint: Use `traceback()` to find where it occurs, add breakpoints / `browser()` calls
-# Hint: look at types of input
-
-library(tidyverse)
-
-# Separate, flatten, and trim values in the vector
-clean <- function(vec) {
-  values <- strsplit(vec, ",")
-  flat_values <- unlist(values)
-  trimmed_values <- str_trim(flat_values)
-  trimmed_values
-}
-
-# Clean vector and get the unique values
-uniquify <- function(vec) {
-  clean_values <- clean(vec)
-  unique_values <- unique(clean_values)
-  unique_values
-}
-
-# Read data and get unique climate values
-get_climates <- function() {
-  planets <- read.csv2(here::here("activities/planets.csv"))
-  unique_climate <- uniquify(planets$climate)
-  unique_climate
-}
-
-# This example originally used in Amanda Gadrow's excellent debugging talk at rstudio::conf 2018,
-# https://github.com/ajmcoqui/debuggingRStudio/blob/b70a3575a3ff5e7867b05fb5e84568abba426c4b/error_example.R
diff --git a/01_exercise/01_debugging_comfy.R b/01_exercise/01_debugging_comfy.R
new file mode 100644
index 0000000..de870fa
--- /dev/null
+++ b/01_exercise/01_debugging_comfy.R
@@ -0,0 +1,58 @@
+# Origin -----------------------------------------------------------------------
+# This example was originally used inJenny Bryan's rstudio::conf(2020) keynote
+# Object of type 'closure' is not subsettable,
+# https://github.com/jennybc/debugging
+
+
+# open 01_sourceme to inspect & review code ---------------------------------------
+# try file.edit()
+
+
+# source functions -------------------------------------------------------------
+# source in 01_exercise/01_sourceme.R 
+
+# view fruit data --------------------------------------------------------------
+
+# successful execution ---------------------------------------------------------
+# confirm function works for berry
+fruit_avg(fruit, "berry")
+
+# error on execution -----------------------------------------------------------
+# observe error
+fruit_avg(fruit, "peach")
+
+# identify location of error ---------------------------------------------------
+# try traceback()
+
+# copy and paste traceback results as a comment here to compare with next exercise
+
+
+# modify options for a richer traceback via rlang ------------------------------
+
+# copy and paste traceback results as a comment here to compare with next exercise
+
+
+# interactive debugging --------------------------------------------------------
+# enter interactive debugger by inserting browser() into the fruit_avg() function
+# trigger interactive debugger by executing function
+
+# use these commands at the Browse[]> prompt to navigate the debugger
+
+# | command | operation               |
+# |---------|-------------------------|
+# | `n`     | next statement          |
+# | `c`     | continue                |
+# | `s`     | step into function call |
+# | `f`     | finish loop / function  |
+# | `where` | show previous calls     |
+# | `Q`     | quit debugger           |
+
+# while in the debugger, explore the objects in your environment
+# with ls.str()
+
+# Can you determine exactly why the bug is occurring?
+# If you have time, try to fix it!
+
+
+
+
diff --git a/01_exercise/01_debugging_solution.R b/01_exercise/01_debugging_solution.R
new file mode 100644
index 0000000..0621b07
--- /dev/null
+++ b/01_exercise/01_debugging_solution.R
@@ -0,0 +1,70 @@
+# Origin -----------------------------------------------------------------------
+# This example was originally used inJenny Bryan's rstudio::conf(2020) keynote
+# Object of type 'closure' is not subsettable,
+# https://github.com/jennybc/debugging
+
+
+# open sourceme to inspect & review code ---------------------------------------
+file.edit("01_exercise/01_sourceme.R")
+
+
+# source functions -------------------------------------------------------------
+# open 01_exercise/01_sourceme.R and click on Source button
+# OR
+source("01_exercise/01_sourceme.R")
+
+
+# view fruit data --------------------------------------------------------------
+fruit
+
+
+# successful execution ---------------------------------------------------------
+# confirm function works for berry
+fruit_avg(fruit, "berry")
+
+# error on execution -----------------------------------------------------------
+# observe error
+fruit_avg(fruit, "peach")
+
+# identify location of error ---------------------------------------------------
+traceback()
+
+# copy and paste traceback results as a comment here to compare with next exercise
+
+
+# modify options for a richer traceback ----------------------------------------
+options(error = rlang::entrace) 
+fruit_avg(fruit, "peach")
+rlang::last_error()
+rlang::last_trace()
+
+# copy and paste traceback results as a comment here to compare with next exercise
+
+
+# interactive debugging --------------------------------------------------------
+# enter interactive debugger by inserting `browser()` statement in  
+# the fruit_avg() function in 01_sourceme.R
+# Restart R, re-source file
+source("01_exercise/01_sourceme.R")
+
+# trigger interactive debugger
+fruit_avg(fruit, "peach")
+
+# use these commands at the Browse[]> prompt to navigate the debugger
+
+# | command | operation               |
+# |---------|-------------------------|
+# | `n`     | next statement          |
+# | `c`     | continue                |
+# | `s`     | step into function call |
+# | `f`     | finish loop / function  |
+# | `where` | show previous calls     |
+# | `Q`     | quit debugger           |
+  
+# while in the debugger, explore the objects in your environment
+# with ls.str()
+
+# Can you determine exactly why the bug is occurring?
+# If you have time, try to fix it!
+
+
diff --git a/01_exercise/01_debugging_spartan.R b/01_exercise/01_debugging_spartan.R
new file mode 100644
index 0000000..a519810
--- /dev/null
+++ b/01_exercise/01_debugging_spartan.R
@@ -0,0 +1,43 @@
+# Origin -----------------------------------------------------------------------
+# This example was originally used inJenny Bryan's rstudio::conf(2020) keynote
+# Object of type 'closure' is not subsettable,
+# https://github.com/jennybc/debugging
+
+
+# open 01_sourceme to inspect & review code ---------------------------------------
+
+
+# source functions -------------------------------------------------------------
+
+
+# view fruit data --------------------------------------------------------------
+
+
+# successful execution ---------------------------------------------------------
+# confirm function works for berry
+fruit_avg(fruit, "berry")
+
+# error on execution -----------------------------------------------------------
+# observe error
+fruit_avg(fruit, "peach")
+
+
+
+# identify location of error ---------------------------------------------------
+
+# copy and paste traceback results as a comment here to compare with next exercise
+
+
+
+# modify options for a richer traceback ----------------------------------------
+
+
+# copy and paste traceback results as a comment here to compare with next exercise
+
+
+# interactive debugging --------------------------------------------------------
+# enter interactive debugger
+
+# Can you determine exactly why the bug is occurring?
+# If you have time, try to fix it!
+
diff --git a/01_exercise/01_sourceme.R b/01_exercise/01_sourceme.R
new file mode 100644
index 0000000..1951b16
--- /dev/null
+++ b/01_exercise/01_sourceme.R
@@ -0,0 +1,14 @@
+fruit <- data.frame(
+  row.names = c("calories", "weight", "yumminess"),
+  blackberry = c(4L, 9L, 6L),
+  blueberry = c(1L, 2L, 8L),
+  peach = c(59L, 150L, 10L),
+  plum = c(30L, 78L, 5L)
+)
+
+fruit_avg <- function(dat, pattern) {
+  cols <- grep(pattern, names(dat))
+  mini_dat <- dat[ , cols]
+  message("Found ", ncol(mini_dat), " fruits!")
+  rowMeans(mini_dat)
+}
\ No newline at end of file
diff --git a/02_debugging_comfy.R b/02_debugging_comfy.R
deleted file mode 100644
index f5c8118..0000000
--- a/02_debugging_comfy.R
+++ /dev/null
@@ -1,17 +0,0 @@
-# dplyr::na_if(x, y) replaces NA values in `x` with `y`
-# it works when x is a data.frame _without_ Date objects, but fails when there is a Date in the df
-# Can you use our debugging tools to figure out where and why it is failing?
-library(dplyr)
-
-test <- tibble(a = lubridate::today() + runif(5) * 30, b = c(1:4, ""), c = c(runif(4), ""), d = c(sample(letters, 4, replace = TRUE), ""))
-test
-
-test %>% na_if("")
-
-# The traceback is easier to understand without the pipe involved
-
-# Also useful to look at the implementation of `na_if()`
-# Can you reproduce the error without using `na_if()`?
-
-# What happens if you remove the date column from the tibble?
-# How could you apply na_if only to non-date columns?
diff --git a/02_debugging_jim.R b/02_debugging_jim.R
deleted file mode 100644
index cbc00f4..0000000
--- a/02_debugging_jim.R
+++ /dev/null
@@ -1,26 +0,0 @@
-# dplyr::na_if(x, y) replaces NA values in `x` with `y`
-# it works when x is a data.frame _without_ Date objects, but fails when there is a Date in the df
-# Can you use our debugging tools to figure out where and why it is failing?
-library(dplyr)
-
-test <- tibble(a = lubridate::today() + runif(5) * 30, b = c(1:4, ""), c = c(runif(4), ""), d = c(sample(letters, 4, replace = TRUE), ""))
-test
-
-test %>% na_if("")
-
-traceback()
-
-# The traceback is easier to understand without the pipe involved
-na_if(test, "")
-
-# Also useful to look at the implementation of `na_if()`
-# We get the same error from
-test[test == ""] <- NA
-traceback()
-
-# And also from
-as.Date("")
-
-# So it seems we need to only use na_if on _character_ columns
-test %>%
-  mutate_if(is.character, ~ na_if(.x, ""))
diff --git a/02_debugging_spartan.R b/02_debugging_spartan.R
deleted file mode 100644
index bfa6306..0000000
--- a/02_debugging_spartan.R
+++ /dev/null
@@ -1,9 +0,0 @@
-# dplyr::na_if(x, y) replaces NA values in `x` with `y`
-# it works when x is a data.frame _without_ Date objects, but fails when there is a Date in the df
-# Can you use our debugging tools to figure out where and why it is failing?
-library(dplyr)
-
-test <- tibble(a = lubridate::today() + runif(5) * 30, b = c(1:4, ""), c = c(runif(4), ""), d = c(sample(letters, 4, replace = TRUE), ""))
-test
-
-test %>% na_if("")
diff --git a/02_exercise/02_debugging_comfy.R b/02_exercise/02_debugging_comfy.R
new file mode 100644
index 0000000..6b0096f
--- /dev/null
+++ b/02_exercise/02_debugging_comfy.R
@@ -0,0 +1,68 @@
+# Origin -----------------------------------------------------------------------
+# This example was originally used inJenny Bryan's rstudio::conf(2020) keynote
+# Object of type 'closure' is not subsettable,
+# https://github.com/jennybc/debugging
+
+# Restart R!
+
+# open 02_sourceme to inspect & review code ---------------------------------------
+# the content is essentially the same as 01_exercise, but the code has been re-structured
+# try file.edit()
+
+
+# source functions -------------------------------------------------------------
+# source in 02_exercise/02_sourceme.R 
+
+# view fruit data --------------------------------------------------------------
+
+
+# successful execution ---------------------------------------------------------
+# confirm function works for berry
+fruit_avg(fruit, "berry")
+
+# error on execution -----------------------------------------------------------
+# observe error
+fruit_avg(fruit, "peach")
+
+# identify location of error via traceback -------------------------------------
+# try traceback()
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+
+# modify options for a richer traceback via rlang ------------------------------
+
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+# How do the tracebacks look different compared to 01_exercise?
+
+# interactive debugging via IDE ------------------------------------------------
+# Restart R
+# enter interactive debugger by inserting a breakpoint in 
+# the fruit_avg() function in 02_sourceme.R
+# re-source file 
+# trigger interactive debugger by executing the function
+
+# navigate the debugger using the buttons at the top of the console
+# be sure to try the "step into" option!
+
+# while in the debugger, explore the objects in your environment
+# with ls.str()
+
+
+# interactive debugging via IDE, again -----------------------------------------
+# Remove breakpoint from 02_sourceme.R
+# Restart R
+# Modify IDE settings to Debug -> On Error -> ??
+# re-source in the file
+
+# trigger console error inspector by executing the function
+
+# explore the "Show Traceback" and "Rerun with Debug" options
+# Where does the debugger drop you in?
+
+# Can you determine exactly why the bug is occurring?
+# If you have time, try to fix it!
+
+
diff --git a/02_exercise/02_debugging_solution.R b/02_exercise/02_debugging_solution.R
new file mode 100644
index 0000000..4959d66
--- /dev/null
+++ b/02_exercise/02_debugging_solution.R
@@ -0,0 +1,80 @@
+# Origin -----------------------------------------------------------------------
+# This example was originally used inJenny Bryan's rstudio::conf(2020) keynote
+# Object of type 'closure' is not subsettable,
+# https://github.com/jennybc/debugging
+
+# Restart R!
+
+# open sourceme to inspect & review code ---------------------------------------
+# the content is essentially the same as 01_exercise, but the code has been re-structured
+file.edit("02_exercise/02_sourceme.R")
+
+
+# source functions -------------------------------------------------------------
+# open 01_exercise/01_sourceme.R and click on Source button
+# OR
+source("02_exercise/02_sourceme.R")
+
+
+# view fruit data --------------------------------------------------------------
+fruit
+
+
+# successful execution ---------------------------------------------------------
+# confirm function works for berry
+fruit_avg(fruit, "berry")
+
+# error on execution -----------------------------------------------------------
+# observe error
+fruit_avg(fruit, "peach")
+
+# identify location of error ---------------------------------------------------
+traceback()
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+
+# modify options for a richer traceback ----------------------------------------
+options(error = rlang::entrace) 
+fruit_avg(fruit, "peach")
+rlang::last_error()
+rlang::last_trace()
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+# How do the tracebacks look different compared to 01_exercise?
+
+# interactive debugging via IDE ------------------------------------------------
+# Restart R
+# enter interactive debugger by inserting a breakpoint in 
+# the fruit_avg() function in 02_sourceme.R
+# re-source file via
+debugSource("02_exercise/02_sourceme.R")
+
+# trigger interactive debugger
+fruit_avg(fruit, "peach")
+
+# navigate the debugger using the buttons at the top of the console
+# be sure to try the "step into" option!
+
+# while in the debugger, explore the objects in your environment
+# with ls.str()
+
+
+# interactive debugging via IDE, again -----------------------------------------
+# Remove breakpoint from 02_sourceme.R
+# Restart R
+# Modify IDE settings to Debug -> On Error -> check Error Inspector
+# re-source in the file
+source("02_exercise/02_sourceme.R")
+
+# trigger console error inspector
+fruit_avg(fruit, "peach")
+
+# explore the "Show Traceback" and "Rerun with Debug" options
+# Where does the debugger drop you in?
+
+# Can you determine exactly why the bug is occurring?
+# If you have time, try to fix it!
+
+
diff --git a/02_exercise/02_debugging_spartan.R b/02_exercise/02_debugging_spartan.R
new file mode 100644
index 0000000..84a66e0
--- /dev/null
+++ b/02_exercise/02_debugging_spartan.R
@@ -0,0 +1,56 @@
+# Origin -----------------------------------------------------------------------
+# This example was originally used inJenny Bryan's rstudio::conf(2020) keynote
+# Object of type 'closure' is not subsettable,
+# https://github.com/jennybc/debugging
+
+# Restart R!
+
+# open 02_sourceme to inspect & review code ---------------------------------------
+# the content is essentially the same as 01_exercise, but the code has been re-structured
+
+
+
+# source functions -------------------------------------------------------------
+# source in 02_exercise/02_sourceme.R 
+
+# view fruit data --------------------------------------------------------------
+
+
+# successful execution ---------------------------------------------------------
+# confirm function works for berry
+fruit_avg(fruit, "berry")
+
+# error on execution -----------------------------------------------------------
+# observe error
+fruit_avg(fruit, "peach")
+
+# identify location of error ---------------------------------------------------
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+
+# modify options for a richer traceback ----------------------------------------
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+# How do the tracebacks look different compared to 01_exercise?
+
+# interactive debugging via IDE ------------------------------------------------
+# Restart R
+# enter interactive debugger by inserting a breakpoint in 
+# the fruit_avg() function in 02_sourceme.R
+
+
+
+
+# interactive debugging via IDE, again -----------------------------------------
+# Remove breakpoint from 02_sourceme.R
+# Restart R
+# Modify IDE settings to Debug -> On Error -> ??
+
+# explore the "Show Traceback" and "Rerun with Debug" options
+# Where does the debugger drop you in?
+
+
+# Can you determine exactly why the bug is occurring?
+# If you have time, try to fix it!
diff --git a/02_exercise/02_sourceme.R b/02_exercise/02_sourceme.R
new file mode 100644
index 0000000..6466ede
--- /dev/null
+++ b/02_exercise/02_sourceme.R
@@ -0,0 +1,33 @@
+fruit <- data.frame(
+  row.names = c("calories", "weight", "yumminess"),
+  blackberry = c(4L, 9L, 6L),
+  blueberry = c(1L, 2L, 8L),
+  peach = c(59L, 150L, 10L),
+  plum = c(30L, 78L, 5L)
+)
+
+find_cols <- function(dat, pattern){
+  grep(pattern, names(dat))
+}
+
+reduce_dat <- function(dat, cols){
+  dat[ , cols]
+}
+
+message_fruit <- function(mini_dat){
+  message("Found ", ncol(mini_dat), " fruits!")
+}
+
+compute_avg <- function(mini_dat){
+  rowMeans(mini_dat)
+}
+
+
+fruit_avg <- function(dat, pattern) {
+  cols <- find_cols(dat, pattern)
+  mini_dat <- reduce_dat(dat, cols)
+  message_fruit(mini_dat)
+  compute_avg(mini_dat)
+}
+
+
diff --git a/03_debugging_comfy.R b/03_debugging_comfy.R
deleted file mode 100644
index 5fbfcd7..0000000
--- a/03_debugging_comfy.R
+++ /dev/null
@@ -1,10 +0,0 @@
-# Given this function, use `trace()` to add a `browser()` statement before the
-# stop
-# Hint: Use as.list(body(fun)) and [[c(1, 2, 3)]] to descend into the expression
-# tree.
-fun <- function() {
-  for (i in 1:10000) {
-    if (i == 9876)
-      stop("Ohno!")
-  }
-}
diff --git a/03_debugging_jim.R b/03_debugging_jim.R
deleted file mode 100644
index d4f26a4..0000000
--- a/03_debugging_jim.R
+++ /dev/null
@@ -1,24 +0,0 @@
-# Given this function, use `trace()` to add a `browser()` statement before the
-# stop
-# Hint: Use as.list(body(fun)) and [[c(1, 2, 3)]] to descend into the expression
-# tree.
-fun <- function() {
-  for (i in 1:10000) {
-    if (i == 9876)
-      stop("Ohno!")
-  }
-}
-
-x <- as.list(body(fun))
-x
-
-as.list(x[[2]])
-
-as.list(x[[c(2, 4)]])
-
-as.list(x[[c(2, 4, 2)]])
-
-as.list(x[[c(2, 4, 2, 3)]])
-
-trace(fun, browser, at = list(c(2, 4, 2, 3)))
-fun()
diff --git a/03_debugging_spartan.R b/03_debugging_spartan.R
deleted file mode 100644
index 19213a0..0000000
--- a/03_debugging_spartan.R
+++ /dev/null
@@ -1,8 +0,0 @@
-# Given this function, use `trace()` to add a `browser()` statement before the
-# stop
-fun <- function() {
-  for (i in 1:10000) {
-    if (i == 9876)
-      stop("Ohno!")
-  }
-}
diff --git a/03_exercise/03_debugging_comfy.R b/03_exercise/03_debugging_comfy.R
new file mode 100644
index 0000000..8ebd4dc
--- /dev/null
+++ b/03_exercise/03_debugging_comfy.R
@@ -0,0 +1,86 @@
+# Origin -----------------------------------------------------------------------
+# This example was originally used inJenny Bryan's rstudio::conf(2020) keynote
+# Object of type 'closure' is not subsettable,
+# https://github.com/jennybc/debugging
+
+# Restart R!
+
+# install the wtfdbg package ---------------------------------------------------
+# the content is essentially the same as 02_exercise, but now the code is no 
+# longer yours!
+# install.packages("devtools")
+devtools::install_github("rstats-wtf/wtfdbg")
+
+
+# attach package ---------------------------------------------------------------
+
+
+# view fruit data --------------------------------------------------------------
+
+# successful execution ---------------------------------------------------------
+# confirm function works for berry
+fruit_avg(fruit, "berry")
+
+# error on execution -----------------------------------------------------------
+# observe error
+fruit_avg(fruit, "peach")
+
+# identify location of error via traceback -------------------------------------
+
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+
+# modify options for a richer traceback via rlang ------------------------------
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+
+# How do the tracebacks look different compared to 02_exercise?
+
+
+# interactive debugging via debugonce() ----------------------------------------
+# set interactive debugger 
+
+# trigger interactive debugger
+
+
+# navigate the debugger using the buttons at the top of the console
+# be sure to try the "step into" option!
+
+# while in the debugger, explore the objects in your environment
+# with ls.str()
+
+
+# interactive debugging via recover error option--------------------------------
+# options(? = ?)
+
+# trigger recover
+
+# explore the frames
+
+# reset options
+
+
+
+# interactive debugging via trace() --------------------------------------------
+
+# investigate the function body with as.list() + body()
+
+# identify a function step to enter debugger
+
+
+# insert browser statement at specified step
+
+# trigger trace
+
+# try ls.str() to get your bearings 
+# and s, s, s, to keep stepping through functions
+
+# cancel tracing
+
+
+# Can you determine exactly why the bug is occurring?
+# If you have time, try to fix it!
+
+
diff --git a/03_exercise/03_debugging_solution.R b/03_exercise/03_debugging_solution.R
new file mode 100644
index 0000000..0d9e0c6
--- /dev/null
+++ b/03_exercise/03_debugging_solution.R
@@ -0,0 +1,100 @@
+# Origin -----------------------------------------------------------------------
+# This example was originally used inJenny Bryan's rstudio::conf(2020) keynote
+# Object of type 'closure' is not subsettable,
+# https://github.com/jennybc/debugging
+
+# Restart R!
+
+# install the wtfdbg package ---------------------------------------------------
+# the content is essentially the same as 02_exercise, but now the code is no 
+# longer yours!
+# install.packages("devtools")
+devtools::install_github("rstats-wtf/wtfdbg")
+
+
+# attach package ---------------------------------------------------------------
+library(wtfdbg)
+
+# view fruit data --------------------------------------------------------------
+fruit
+
+# successful execution ---------------------------------------------------------
+# confirm function works for berry
+fruit_avg(fruit, "berry")
+
+# error on execution -----------------------------------------------------------
+# observe error
+fruit_avg(fruit, "peach")
+
+# identify location of error ---------------------------------------------------
+traceback()
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+
+# modify options for a richer traceback ----------------------------------------
+options(error = rlang::entrace) 
+fruit_avg(fruit, "peach")
+rlang::last_error()
+rlang::last_trace()
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+# How do the tracebacks look different compared to 02_exercise?
+
+
+# interactive debugging via debugonce-------------------------------------------
+# set interactive debugger 
+debugonce(fruit_avg)
+# trigger interactive debugger
+fruit_avg(fruit, "peach")
+
+# navigate the debugger using the buttons at the top of the console
+# be sure to try the "step into" option!
+
+# while in the debugger, explore the objects in your environment
+# with ls.str()
+
+
+# interactive debugging via recover error option--------------------------------
+options(error = recover)
+
+# trigger recover
+fruit_avg(fruit, "peach")
+# explore the frames
+
+# reset options
+options(error = NULL)
+
+
+
+# interactive debugging via trace ----------------------------------------------
+
+# investigate the function body
+x <- as.list(body(fruit_avg))
+View(x)
+
+# identify a function step to enter debugger
+as.list(x[[5]][[1]])
+# equivalent notation
+as.list(x[[c(5, 1)]])
+
+
+# insert browser statement at specified step
+trace(fruit_avg, browser, at = list(c(5, 1)))
+
+# trigger trace
+fruit_avg(fruit, "peach")
+
+# try ls.str() to get your bearings 
+# and s, s, s, to keep stepping through functions
+
+# cancel tracing
+untrace(fruit_avg)
+
+
+# Can you determine exactly why the bug is occurring?
+# If you have time, try to fix it!
+
+
+
diff --git a/03_exercise/03_debugging_spartan.R b/03_exercise/03_debugging_spartan.R
new file mode 100644
index 0000000..63d84a0
--- /dev/null
+++ b/03_exercise/03_debugging_spartan.R
@@ -0,0 +1,55 @@
+# Origin -----------------------------------------------------------------------
+# This example was originally used inJenny Bryan's rstudio::conf(2020) keynote
+# Object of type 'closure' is not subsettable,
+# https://github.com/jennybc/debugging
+
+# Restart R!
+
+# install the wtfdbg package ---------------------------------------------------
+# the content is essentially the same as 02_exercise, but now the code is no 
+# longer yours!
+# install.packages("devtools")
+devtools::install_github("rstats-wtf/wtfdbg")
+
+
+# attach package ---------------------------------------------------------------
+
+
+# view fruit data --------------------------------------------------------------
+
+# successful execution ---------------------------------------------------------
+# confirm function works for berry
+fruit_avg(fruit, "berry")
+
+# error on execution -----------------------------------------------------------
+# observe error
+fruit_avg(fruit, "peach")
+
+# identify location of error ---------------------------------------------------
+
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+
+# modify options for a richer traceback ----------------------------------------
+
+# copy and paste traceback results as a comment here to compare with other exercises
+
+
+# How do the tracebacks look different compared to 02_exercise?
+
+
+# interactive debugging via debugonce() ----------------------------------------
+
+
+
+# interactive debugging via recover error option--------------------------------
+
+
+
+# interactive debugging via trace() ----------------------------------------------
+
+
+
+# Can you determine exactly why the bug is occurring?
+# If you have time, try to fix it!
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..6ffd534
--- /dev/null
+++ b/README.md
@@ -0,0 +1,32 @@
+# Get started 
+
+```r
+usethis::use_course("rstats-wtf/wtf-debugging")
+```
+
+# Exercises
+
+* `01_exercise` practice debugging your own code
+
+* `02_exercise` practice debugging your own code with RStudio IDE features
+
+* `03_exercise` practice debugging others' code
+
+Choose your own adventure!
+
+* `0X_debugging_spartan.R` (directions to explore without suggested code)
+
+* `0X_debugging_comfy.R` (directions to explore with suggested code)
+
+* `0X_debugging_solution.R` (directions to explore with code solutions)
+
+
+# Restart R
+
+Remember to restart R as indicated. In the RStudio IDE:
+
+* Session -> Restart R, or
+
+* Ctrl + Shift + F10 (Windows),
+
+* Cmd + Shift + 0 / Cmd + Shift + F10 (Mac)
\ No newline at end of file
diff --git a/planets.csv b/planets.csv
deleted file mode 100644
index ef1a435..0000000
--- a/planets.csv
+++ /dev/null
@@ -1,11 +0,0 @@
-"name";"rotation_period";"orbital_period";"diameter";"climate";"gravity";"terrain";"surface_water";"population";"edited"
-"Alderaan";"24";"364";"12500";"temperate";"1 standard";"grasslands, mountains";"40";"2000000000";"2014-12-20T20:58:18.420000Z"
-"Yavin IV";"24";"4818";"10200";"temperate, tropical";"1 standard";"jungle, rainforests";"8";"1000";"2014-12-21T20:58:18.421000Z"
-"Hoth";"23";"549";"7200";"frozen";"1.1 standard";"tundra, ice caves, mountain ranges";"100";"unknown";"2014-12-22T20:58:18.423000Z"
-"Dagobah";"23";"341";"8900";"murky";"N/A";"swamp, jungles";"8";"unknown";"2014-12-23T20:58:18.425000Z"
-"Bespin";"12";"5110";"118000";"temperate";"1.5 (surface), 1 standard (Cloud City)";"gas giant";"0";"6000000";"2014-12-24T20:58:18.427000Z"
-"Endor";"18";"402";"4900";"temperate";"0.85 standard";"forests, mountains, lakes";"8";"30000000";"2014-12-25T20:58:18.429000Z"
-"Naboo";"26";"312";"12120";"temperate";"1 standard";"grassy hills, swamps, forests, mountains";"12";"4500000000";"2014-12-26T20:58:18.430000Z"
-"Coruscant";"24";"368";"12240";"temperate";"1 standard";"cityscape, mountains";"unknown";"1000000000000";"2014-12-27T20:58:18.432000Z"
-"Kamino";"27";"463";"19720";"temperate";"1 standard";"ocean";"100";"1000000000";"2014-12-28T20:58:18.434000Z"
-"Geonosis";"30";"256";"11370";"temperate, arid";"0.9 standard";"rock, desert, mountain, barren";"5";"100000000000";"2014-12-29T20:58:18.437000Z"
diff --git a/shhh-secret-fixed-fruit_avg.R b/shhh-secret-fixed-fruit_avg.R
new file mode 100644
index 0000000..d1bbc87
--- /dev/null
+++ b/shhh-secret-fixed-fruit_avg.R
@@ -0,0 +1,18 @@
+# source of error: 
+#
+# when only one fruit is found,
+# mini_dat <- dat[ , cols]
+# returns a vector instead of a data frame
+#
+# e.g., fruit[, 1:2] vs fruit[, 1]
+#
+# this can be fixed with the drop argument
+# fruit[, 1, drop = FALSE]
+
+# here is this fixed fruit_avg()
+fruit_avg <- function(dat, pattern) {
+  cols <- grep(pattern, names(dat))
+  mini_dat <- dat[ , cols, drop = FALSE]
+  message("Found ", ncol(mini_dat), " fruits!")
+  rowMeans(mini_dat)
+}