Remove .Rdata demonstration.

Feedback from UChicago tutorial was that it caused confusion. Also,
need to shorten tutorial overall.

Author: jdblischak

analysis/challenge.Rmd

@@ -32,31 +32,15 @@ steps:
 
 The analysis purposefully contains various issues that make it difficult to
 reproduce. Open the file `spotify.Rmd` by clicking on it in the RStudio Files
-pane. In the Editor pane, click on "Run" and then click on "Run All" to execute
-all the code chunks in the R console (Ctrl/Cmd+Alt+Enter). Note that the code
-completes and produces a plot in the Plots pane.
-
-Next click the Knit button to re-build the document. This time the code fails
-due to an error. The difference is because RStudio knits Rmd files in a clean
-R session. In contrast, the R session currently running in the R console already
-had all the analysis variables created because the workspace was restored. This
-is why you want to avoid saving your workspace: it can make it appear that your
-code is running when it is actually contains errors. In fact, if you scroll
-back up through the R console history, you'll see that some errors did occur.
-But the analysis still completed since the intermediate objects were already
-available.
-
-To fix the workspace issue, first go to the Files pane and delete the file
-`.RData` that contains the saved workspace. Second, go to "Tools" -> "Global
-Options...". Unclick the checkbox "Restore .RData into workspace at startup" and
-change the dropdown "Save workspace to to .RData on exit" to Never.
-
-![](assets/rstudio-workspace.png)
-
-Now you can proceed to fix the analysis one error at a time. Click on Knit to
-produce the first error. Then click on "Output" to see the lines in the Rmd
+pane.
+
+Next click the Knit button to re-build the document. The code fails
+due to an error. Click on "Output" to see the lines in the Rmd
 file where the error occurred.
 
+Working together in small groups, reproduce the analysis by fixing the errors.
+Below are hints on how to fix each error you will find.
+
 ## File paths
 
 The first error you will encounter is below: