Assignment for Class 6

Please complete before the next class.

Make sure that you’ve completed all previous HW first.

An Extra Video

If you need a bit of extra help on the basics of R, you might find this video helpful. It’s a duplication of the material I discussed in class.

Loading Data

Read and review your notes, my notes, and my slides over the basics of loading data into R. Answer the review questions throughout the document. Remember to practice!

Like the previous assignment, this is a tedious assignment–you’ll need to work carefully. I suggesting spreading the exercise over several different sessions to give you time to digest the ideas. Don’t rush it. The previous assignment covered many simple ideas–this assignment covers a fewer, but more complex ideas.
I’ve found that working in groups helps when you are stuck.
I try to write exam questions that students who can do the review exercises will answer correctly and quickly (and that others will answer incorrectly and/or slowly).
When you can’t get your code to work, it’s usually just a missing parenthesis or quotation mark. It’s not that you’re making a huge mistake. Huamns can sitll mkae snese wehn tehre are tpyos, but not computers! Check your code for typos carefully. Run your script one line at a time, from top to bottom, to find mistakes. As examples, most mistakes are like the following:

b <- c("Male", "Female)  # missing the second " after "Female"
exp(23  # forgot to close a parentheses
log(10 base = 2)  # missing comma between arguments

a <- c(1, 2, 3)
mean(A)  # R is case-sensitive--there's an object "a", but no object "A" 
mena(a)  # misspelled function name
Mean(a)  # R is case-senstive

Prepare for the Exam

You should bring a pencil ~~and your calculator~~ (calculator not needed for the first exam). I will bring scantron forms. We will meet in our usual time and place, and you will have the full class period to complete the exam. It will be about 30 questions, and I design it so that no one feels rushed.

When I write the exam, I write questions that students who can do (and have done) the review exercises will answer correctly. If you can do the review exercises, then you will do well on the exam. (The review exercises are describe across each of the HW assignments on the course schedule.)

For the computational questions, you should be able to do the review exercises while relying on the notes quite heavily (but perhaps not entirely). If you can do the R exercises successfully while relying on the notes “somewhat”, then you’re well-prepared for the exam.
For the conceptual questions, you should be able to answer them without relying on references at all–you should be able to do the conceptual exercises “closed-book.”

When studying for the exam, just make sure you can handle the review exercises. If you can do the review exercises, then you have learned what I wanted and will do well on the exam.

When I write the exam, I just pick a representative set of review exercises and use those to inspire multiple choice questions. Some exam questions will be nearly identical to the review exercises. Others will be a bit different. But if you can complete the review exercises, you can answer the exam questions.

Look back through each HW and make sure you’ve completed all the review exercises (spread across slides, FPP chs. 1-2, and notes).

Carlisle Rainey