Such Material!

1
Such Material!

• So Content!

2
Class Discussion Time

• Why do we discuss a statistic but we do not
  discuss a mathematic or a physic?
• A gentle warning if we do not have a productive
  student-lead discussion, I will instead turn this
  into an individual writing prompt. Timed, of
  course.

3
Think, Show, and Tell

• Think
• Before we can solve the problem, we will need to
  spend serious time considering it seriously.
• Show
• An answer without a method or without evidence is
  at best an opinion, at worst a lie.
• Tell
• Even people who have taken Statistics need
  answers to be broken down. (Let alone those who
  have not!)

4
Types of Summaries of Data

• Visual
• Commonly used in Think and Show
• Numerical
• Commonly used in Show
• Verbal
• Commonly used in Think and Tell
• Any complete analysis of data almost always
  includes all three of these.

5
More About Data

• Numerical data (quantitative)
• Usually counts of things
• Names or labels (categorical/qualitative)
• The Five Ws
• Who
• What
• When
• Where
• Why
• How

6
Context

• Without context, data is just stuff.
• If you cant answer the who and the what you
  dont have data.
• And you dont have any useful information.

7
Who - Subjects

• Answers the question, About whom (or what) has
  data been collected?
• When data is organized into a data table, the
  rows are generally the who.
• The who can be referred to as
• Respondents
• Subjects
• Participants
• Experimental units
• Records
• Cases

p. 9
8
What - Variables

• Characteristics about each individual whose value
  varies from case to case.
• Usually the columns.
• Categorical (qualitative) the variable names
  categories or answers questions about how cases
  fall into those categories.
• Quantitative a variable measured in units or
  answers questions about the quantity of what is
  measured, how many or how much.

9
Two Houses, Both Alike In Dignity

• Categorical Variables are variables which have
  data that are names, labels, or indicators.
• These can be numbers, such as a social security
  number or zip code, or in some situationsage.
• Quantitative Variables are variables which have
  data that are counts or measurements within a
  category.
• These will be numbers, although not all numbers
  are this kind of variable.
• There will be units of measurement.

10
Categorical vs Quantitative

• What is the category label.
• Who is the individuals counted in the category.

• Quantity for each individual subject.
• Must include units of measurement.

11
Categorical or Quantitative?

• Gender
• Age
• 17, 21, 44, 76

12
Univariate or Bivariate

• Univariate data has only one variable.
• Bivariate data has two variables.
• Multivariate data has more than one variable.
• In this class, we do certain specific things with
  bivariate data, and then most of what we do will
  be done with univariate data.

13
Question Words on Parade

• The Who, What, When, Where, Why, and How are all
  very important in Statistics.
• You need the Who and the What just to have data.
• You need the Why or else the data is not
  meaningful.
• The When and the Where help you to determine if
  the data can be applied another way.
• The How lets you know if analyzing the data is
  meaningful and worthwhile by determining if the
  method of gathering data was reliable.

14
Who

• Who is the data being collected about?
• Sometimes the who is not people, but instead
  something else.
• So a more universal question is Who/What is the
  data being collected about?
• While it could be importantthis question is not
  the same as asking who did the collecting.
• Although if we know who did the collecting, this
  can help us spot bias.

15
What

• What data was actually collected?
• More than one variable might have been collected.
• The collected variables will, in the context of
  the study, be either categorical or quantitative,
  but never both.

16
When/Where

• While not as necessary as the Who or What, this
  information is still context.
• How many studies from before there were internet
  or cell phones are still valid today?
• Is a study done in California valid in Alaska?
• Would knowing about the job market in Idaho Falls
  tell you about the job market in Pocatello?

17
Why

• Why was the data collected?
• Someone took time to get this data.
• This is the presumable motivation for gathering
  it.
• Even if it is not stated, it can sometimes be
  very obvious.
• The Neilson Company estimates ratings for
  television shows. Why?
• All about the Benjamins!

18
How

• How was the data collected, and were the methods
  reliable?
• For now you can only take your best intuitive
  guess at this.
• There is an entire unit on how to gather data
  reliably.
• It is Unit 3.
• We are in Unit 1.
• So you are not ready to be all fancy about it
  yet, and I get that. Do your best.

19
The Five Ws

• A Consumer Reports article on energy bars gave
  the brand name, flavor, price, number of
  calories, and grams of protein and fat.

20
Problem 2

• Who?
• Who The 30 other companies
• Not Fortune Magazine and not the company doing
  the study.
• What?
• What 401(k) participation rates
• When?
• When Not given
• 1992 is simply when the article was published.

21
Problem 2

• Where?
• Where Not given
• Why?
• Why To see if the companys participation in
  401(k) was low compared to other companies.
• How?
• How The 30 companies were asked what their
  participation rates are.
• After we do unit 3, you would have a more
  detailed answer, such as commenting on the
  sampling procedure used.

22
Problem 2

• For each variable (What Answer), we need to
  identify if it is categorical, or quantitative.
• The variable, 401(k) participation rates, is
  likely being used as a quantitative variable.
• The participation rate does not have specified
  units, although the units are most likely
  percentage of the total employees.
• Even though the instructions for doing this occur
  after the instructions to identify the question
  words, you can totally do this while you are
  doing the what.
• It is more efficient, in fact.

23
Problem 2, Final Output

• Who The 30 other companies
• What 401(k) participation rates (Quantitative
  Units of total employees)
• When Not given
• Where Not given
• Why To see if the companys participation in
  401(k) was low compared to other companies.
• How The 30 companies were asked what their
  participation rates are.

24
Assignments

• Finish Reading Chapters 1 and 2 if you have not
  already.
• Chapter 2 exercises 2-7, 25, 26
• Due Thursday
• You can turn them in sooner, either physically or
  via e-mail, and that is fine with me.
• There will be a chapters 1-3 Quiz on Friday
• We just finished discussing chapter 2, so a good
  student would know what that means in terms of
  the reading.
• Ill cut you some slackyou only need to read
  chapter 3 thru the top part of page 31 for
  tomorrow. Read the rest for Thursday.

25
More Unsupporting Cast

• On yesterdays episode we talked about Mr.
  Cheeseburger and then need for ridiculously
  levels of clarity.
• Today we will focus on the Casual Observer, the
  Hasty Generalizer and the Exemplar, which might
  seem like the same at first, but are actually
  three very differently flawed archetypes.
• They do, however, have in common that they come
  to their conclusions far too easily.

26
The Casual Observer

• This phrase normally refers to a person who is
  looking at the situation, but does not have any
  particularly strong background in what is going
  on and who does not look any deeper than what is
  on the surface.
• We are using it to refer to someone who does
  exactly that with exactly the same restrictions.
• Casual Observers are easily swayed by misleading
  pictures and misinformation because they are only
  looking at what is immediately available.

27
The Casual Observer

• The reason it is important to be aware of these
  observers is that the reason we must be concise
  is because if we take yawn-worthy lengths of time
  to get to our true point, some people will have
  totally tapped out by then.
• We need to get to our points in a timely manner
  so that a casual observer gets the information
  before they would otherwise give up.

28
The Hasty Generalizer

• A hasty generalization is when a person assumes
  that something which is/seems true in some
  situation is also actually true in many, if not
  all, similar situations.
• The person I refer to here is a little different
  than that, though.
• In this context I am referring to a person who
  just wants you to get to the conveniently
  digested point, not really caring how you got
  there, so they can get on with their day.

29
The Hasty Generalizer

• Such a person will typically latch on the first
  solid point you make and assume that the rest of
  what you said is meaningless, unless a better
  point comes along.
• At which point they tend to abandon the original
  point in favor of the new one.
• It is important to be complete while being
  concise in order to get around this. Your entire
  point needs to be visible in a relatively concise
  and clear manner for someone trying to breeze
  through it to get the full effect.

30
The Exemplar

• Normally an exemplar would be someone who has
  done things in a way that sets a superior example
  for others to follow.
• In this case, though, I am referring to a person
  who fixates on a specific example of something
  happening, and assumes that it is way more
  important than it is.
• Interestingly enough, that is actually closer to
  a hasty generalization, most of the time, than it
  is to anything else.

31
The Exemplar

• For example, this person assumes that 9 out of
  10 dentists approving of a particular dental
  product means that 1 of them did notand that it
  should be closely investigated as to exactly why.
• This kind of person also assumes that there is
  genuine scientific controversy as to the
  existence of global warming because there are
  scientists which are unconvinced.
• This kind of person might get pulled over once
  for running a stop sign and then immediately
  decides that cops will always pull you over for
  running stop signs.

32
The Exemplar

• This sort of person tends to believe that one
  rather unlikely example should hold just as much
  weight as the ongoing, consistent outcomewhich
  is the opposite of that example.
• It is very important that we address any and all
  unusual results in our efforts to avoid someone
  taking them and running with them,
  metaphorically, which means taking time to
  explore possible reasons that strange results
  occurred.

33
Quiz Bulletpoints

• Know what T-S-T stands for and what each one
  means.
• Know how to identify the 5 Ws and How in a
  study.
• Know the difference between a qualitative and
  quantitative variable.
• Know how to find percentages from a contingency
  table.
• Know the area principle.