## Quiz 08: Policies and Information

### Location, Date, and Time

Conflicts: There will be no conflict quiz as students are able to choose the time and date of their quiz.

### Quiz Content

All quizzes are cumulative. Previous material can reappear on a later quiz.

Designing a Graphic

• What role does a graphic play in expressing the data’s narrative?
• How does the Simpson’s Paradox yield alternative explanations for data when shown on a graph?
• Why does apophenia require a more methodological approach to interpreting patterns on a graph?
• How can graphs be used to lie with statistics?

CRAP

• What paradigm can be used to assess the quality of graphics?
• Why do we want to have a framework for assessing a graphic?
• How is CRAP related to Gesalt tenets?
• What kind of techniques can be used to distort the meaning of the data?
• Why are pie charts a poor choice to visualize data?

Chart Junk

• What kind of effect does chart junk have on the interpretation of a graph?
• How is chart junk related to the “Lie” Factor?
• What does it mean if the Lie factor is greater than 1? What if it is less than 1?

Modern Graphics

• What are the different types of graphics?
• How are animated graphics created?
• Where should animated graphs be used?
• Why are interactive graphics useful?

7.2: Grammar of Data

Provided with: Data Transformation Cheatsheet

Interrogating Data

• Why do we want data to be in a tidy format when asking questions of it?
• How can we phrase questions that promote effective wrangling of data?
• Describe the five verbs related to data manipulation.

dplyr

• What is dplyr?
• How is dplyr different than base R?
• What are the pros and cons of using dplyr vs. base R in manipulating data?
• How is a pipe operator useful?

Split-Apply-Combine

• What is the Split-Apply-Combine paradigm? What occurs during each stage of its stages?
• How is Split-Apply-Combine related to the MapReduce algorithm used by Hadoop to process large data?
• Why is Split-Apply-Combine an effective framework for statistical computing?

7.3: Joins

Databases:

• How is the idea of databases similar to the idea of R’s data.frame?
• Why are databases useful for analyses?

Keys and Relationships

• How does a primary key differ from a foreign key?
• What kinds of relationships exist between two or more tables?

Joins

• What are the different kinds of joins?
• Why should we use join instead of naively combining data?
• When does right_join() return results similar to left_join()?

### Materials Needed

• Preferably, a rested mind and non-broken hands that can type.

### Policies

• All answers must be reasonably simplified.
• Decimals answers must contain two significant digits.
• Grading will be done as follows:

If you have a technical issue while answering questions or need assistance with opening or starting the quiz, please alert the proctor.

Do not leave the CBTF without filing an issue with the proctor if something goes wrong.

### DRES

Have a testing accommodation? Please see how the CBTF handles Letters of Accommodation.

The short version: Please bring a copy of the Letter of Accommodation to the CBTF Proctors prior to the test taking place.

In short, don’t cheat. Keep your eyes on your own quiz. Do not discuss the quiz with your friends after you have taken it. Any violation will be punished as harshly as possible.

The best way to study for a STAT 385 quiz is by writing and reading code. Try to take an idea in STAT 385 and apply it to your own work.

With this being said, there are three other resources that may assist your studies:

• Topic Outline (Above)
• Lecture Code
• Homework

Again, the best way to study is to do programming in some fashion. Whether that be writing code or explaining how code works to someone else.

Consider using resources such as:

1. RStudio Cloud Primers for interactive practice.
2. Exercise problems listed in a given section of the readings.

Do not spend time memorizing lecture slides. You will not see any verbatim questions.

Do not try pulling an all-nighter. You can schedule your quiz anytime between a time window. To program efficiently, you need sleep despite the quote:

“Programmers are an organism that turns caffeine into code.”

#### What kind of question types are on the quiz?

There are generally four types of problems:

• True / False
• Multiple Selection (e.g. select ALL correct answers from a list)
• Fill in the blank
• Writing Code

#### How many problems are on the quiz?

Only one question with 15012391 subquestions. In all seriousness, do not fixate on a number. There will be a reasonable amount of questions for the time period.

#### How long will it take to do the quiz?

Depending on your background, the quiz may take:

• Prior R in-depth experience: 25 minutes
• Some R experience: 35 minutes
• No R experience: 50 minutes

Avoid fixating on time. Life will come and go more quickly than you realize. Focus more on the content.

#### When will the quiz be returned?

As all problems are automatically graded, we should be able to post the quiz results after the examination window closes.

No.

#### We got our grades back, now will the quiz be curved?

No. Curving is only done sparingly at the end of the semester. Individual assignments are not modified.