Today: Dummy variables.
Dummy variables in a multiple regression, regression wrap up.
Looking back in regression, weve looked at how an interval
data response y changes as an interval data explanatory
variable x. Changes.
Example: Number of books read (y)
One more example of a hypothesis test
Chapter 10: Scatterplots
If time: Joy of Stats 200 Countries, 200 Years
You should know this.
You should be familiar with all of this, but dont waste
too much time memorizing.
Alzhiemers Onset and Gender (From Ch.7 ex

A few more notes about Z
SPSS and the normal curve
Chapter 6: Samples vs. Populations
Convenience/accidental sampling: why online polls suck
Last day, we looked at the relationship between standard
scores (zscores) and raw scores.
For example, if the a
This time: Some ANOVA theory, two large examples.
Last time, we started on ANOVA, or AnOVa, which is short for
Analysis Of Variance.
AnOVa is a set of statistical methods designed to answer one
question Where is the variance coming from?
A less formal way
We took a survey of people in four career fields and found if
they were left or right handed.
These are the observed counts.
Most of the respondents are right handed except for in the
athletics field, where a few more than half are left handed.
We want to
Wed, June 26, (Lecture 82). Nonlinearity.
Significance test for correlation
Rsquared, SSE, and SST.
Correlation in SPSS.
Last time, we looked at scatterplots, which show the
interaction between two variables, and correlation.
The correlation coefficient
Odds ratio, Odds ratio test for independence,
chisquared statistic.
Announcements:
Assignment 5 is live on webpage. Due Wed Aug 1 at 4:30pm.
(9 days, 1 hour, 58.5 minutes)
Final exam is Aug 9.
Review session Aug 7? 8? What works for you?
Deadline for sug
SPSS: Expected frequencies, chisquared test.
Indepth example: Age groups and radio choices.
Dealing with small frequencies.
Quick Example: Handedness and Careers
Last time we tested whether one nominal variable was
independent of another.
We did this by
 Regression example
 Multiple regression. SPSS for multiple regression.
 Prediction examples.
 Midterm is still being marked so no comment.
 The rest of assignment 4 is up, there are three questions for
marks. Due Wednesday at 4:30.
9 Lectures left W
Todays Agenda

SPSS: Boxplots
Ratios
Crosstabs
Conditionals
Association and causation
SPSS: Crosstabs
Relevant text: P.5460 Chapter 2
From last time:
 Boxplots are good for visualizing the general trend in
interval data.
 They show everything in the _
Twosample ttests.
 Independent samples
 Pooled standard devation
 The equal variance assumption
Last time, we used the mean of one sample to test against the
hypothesis that the true mean was a particular value.
Onesided test:
Twosided test:
We als
Todays agenda:

SPSS Demo: Entering data
SPSS Demo: Get the mean, median, histogram, skew
SPSS Demo: Putting graphs into word
Quartiles and the Five Number Summary
Read for today: All of Chapter 3 (Measures of Central Tendacy)
Correction
 The mean of 4,
This time: A correction, ANOVA with review, student reviews.
Assignment 4 is marked and in the workshop.
Correction from Mondays lecture.
A more detailed account of why this is so is in Wk13_Extra on
webpage, but its for interest only.
What I said:
The pr
Formula for linear models.
Prediction, extrapolation, significance test against zero
slope.
Last time, we looked the linear regression formula.
Its the line that fits the data best. The Pearson correlation
can be considered a measure of how well that line
SPSS on two independent samples.
Two sample test with proportions.
Paired ttest (with more SPSS)
State of the course address:
The Final exam is Aug 9, 3:30pm 6:30pm in B9201 in the
Burnaby Campus. (One or two hallways off from AQ on the
north side)
After
Problem 10.19
Problem 10.21
Using correlation to see if paired
Begin Chapter 11: The regression equation.
Problem 10.19: Do reading and television viewing compete for
leisure time? We have a random sample of 10 children with
X: Books read last year
0
7
2
STAT 203 Lecture 41.

The normal distribution is symmetric.
Getting the probability from between two zscores
Translating standard scores to and from raw scores.
Extreme values beyond the table.
So Majestic!
Text from last Friday:
Say a value X followed
Midterm 2, Question 2, 3, 4.
Odds. Odds Ratio.
Fractal by Emma Taylor.
Question 2: Test the null that the mean is 40 against the
twotailed alternative.
= 46, s =6, n = 9
First, identify: We only have one sample mean, so this is a
_ .We are given that it
A full analysis example
Multiple correlations
Partial correlations
New Dataset: Confidence
This is a dataset taken of the confidence scales of 41
employees some years ago using 4 facets of confidence
(Physical, Appearance, Emotional, and Problem Solving,
Review Pvalues
Type I and Type II Errors
Talk to your kids about pvalue, or someone else will.
pvalue: If H0 is true, what would the chances of observing as
much evidence as we did?
If the pvalue is small, then the observed statistic is very
unlikely

Identify the appropriate test
One proportion test
Two samples independent
Two samples paired
Estimate the correlation
Significant correlation
What test should you do? Example 1
You want to find if more than 90% of skytrain users have valid
fare.
1. The
Todays Agenda:

More examples with probability
The normal distribution
Probability and the normal distribution
Z scores
You should be about halfway through Chapter 5 by now.
(For assignment as well)
The probability rules.
Probability = ways event occurs
Today:
 InterQuartile Range,
 Outliers,
 Boxplots.
Reading for today: Start Chapter 4.
Quartiles and the Five Number Summary
 The five numbers are the Minimum (Q0), Lower
Quartile (Q1), Median (Q2), Upper Quartile (Q3),
and Maximum (Q4).
 Q1 means b
Ttest in SPSS
Hypothesis tests of proportions
Confidence Intervals (End of chapter 6 material)
Definition of pvalue:
The probability of getting evidence as strong as
you did assuming that the null hypothesis is true.
A smaller pvalue means that its les
This time: ANOVA examples, course wrapup.
ANOVA/Review example: We have a zombie outbreak. Weve
identified the cause: the nefarious Bayes Virus.
So far, we have five possible treatments were testing by
administering them to 40 petri dishes of infected bl
Welcome to STAT203 Statistics for Social Sciences
Todays agenda:

Introduction
Policies
How to win at statistics.
Ch. 2 start: Nominal, Ordinal, and Interval data.
Video: Joy of Stats  Florence Nightingale
My Assumption is at the beginning of the semest
What is inference?
Hypothesis tests in t
This weeks lectures are actually a combination of chapter 6
and chapter 7 material.
Knowing something about a sample, on its own, isnt very
useful.
Information about the population as a whole is much more
useful fo

Stratified Samples
Systematic Samples
Samples can vary
Standard Error

From last time: A sample is a small collection we observe and
assume is representative of a larger sample.
Example: You havent seen Vancouver, youve seen only seen a
small part of i
 Midterm Practice Problems Today!
Practice Midterm:
Q1: Describe this distribution.
Q2: Statistic or Parameter
Q3: Probability
Describe this distribution
Use the checklist:
Center:
where is the middle, if applicable
Spread: how far from the middle does d
My friend Dave has terrible luck. He bought a computer, and
within 11 months (still under warranty) he had replaced the
bluetooth (twice),
motherboard,
heat sink, fans, and media button bar (twice),
hard drive (four times!)
and his company loyalty.
After