Introduction to Statistics for the Social Sciences

STATISTICS 203

Fall 2010

Textbook: Elementary Statistics in Social Research 11th Edition, Levin, Fox, and Forde

Instructor: Darby Thompson

[email protected]

Stat203

of 13 Fall 2011 - Week 1, Lecture 1 Goals

I will NOT:

- make you all statisticians

- convince you that statistics is the best thing ever

- ask you to memorize lots of formulae

- teach you anything irrelevant or useless

After taking this class you WILL be able to:

- understand why statistics are useful

- perform some basic analyses

- interpret results in paper and media

- improve your critical thinking

2 Important Information

Course Notes: All notes will be available on my website: http://www.stat.sfu.ca/~dthompso/ There will be gaps completed during lectures.

Statistics Workshop: Open every day (K9514). TAs are available to answer questions or help with homework. Access to computing and statistical software: http://www.stat.sfu.ca/teaching/workshop/

Office Hours: Tuesdays 12:00 – 1:00PM Room K10564 These are only if you have administrative or grading questions or have not found the workshop helpful. Go to the WORKSHOP FIRST. I will NOT fill in the gaps in your course notes.

Stat203

of 13 Fall 2011 - Week 1, Lecture 1 Policy on Late Assignments and Academic Integrity

Assignments MUST:

- be handed in by the deadline Late assignments will not be marked

- be placed in the box outside the Stats Workshop Assignments later discovered in the wrong box will not be marked

- have student name, course number, and student number clearly in the top right- hand corner

- have computer output integrated directly into the answer (not stapled to the back)

- be the work of the student

Collaboration on assignments is encouraged, but the work must be the student’s own In the case of two or more assignments or portions thereof, which appear to be duplicates or work of another student, none will receive marks

4 Exams

2 Midterms

- mixture of multiple choice and short answer

- related to both lecture material, textbook, in-class examples, and homework questions

- open-book

- calculators are permitted, but will not be necessary

Policy on missed-midterms:

- if you notify me in advance, a make-up date/time may be possible

- if you miss a midterm (with health-related excuse), weight will be transferred to the final

Stat203

of 13 Fall 2011 - Week 1, Lecture 1 Grading and Dates

4 Assignments = 15% 2 Midterms = 40% Final = 45%

Dates Assignments Set Sep 21 1 Set Oct 12 2 Set Nov 2 3 Set Nov 16 4 Midterms 1 Oct 19 2 Nov 23 Final Dec 17

If you will be unable to write a midterm or exam on the scheduled day, notify me in advance.

6 Grading Scheme

Grade Percentage Descriptor A+ 95-100 Exceptional A 90-94 Outstanding A- 85-89 Excellent B+ 80-84 Very Good B 75-79 Good B- 70-74 Minimally Good C+ 65-69 Satisfactory C 60-64 Satisfactory C- 55-59 Minimally Satisfactory D 50-54 Unsatisfactory F < 50 Very unsatisfactory

Stat203

of 13 Fall 2011 - Week 1, Lecture 1 Topics

1. Introduction and Role of Statistics in Social Science (Chapters 1)

2. Types of Data and Graphical Presentation of Data (Chapter 2)

3. Measures of Central Tendency (Chapter 3)

4. Variability (Chapter 4)

5. Probability and the Normal Distribution (Chapter 5)

6. Samples and Populations (Chapter 6)

7. Hypothesis Testing (Chapter 7)

8. Correlation (Chapter 10)

9. Non-Parametric Significance Testing (Chapter 9)

10. Regression (Chapter 11)

11. Non-Parametric Correlation (Chapter 12)

8 You will need software …

Software will be required to complete the assignments.

All in-class examples will be completed using JMP (Download free at http://www.sfu.ca/itservices/software/ ) * if you have installed JMP previously, uninstall completely and then install JMP8

I will not be giving tutorials on JMP, but will perform all analyses in class and will post some videos to the class website.

Feel free to use any software package you are familiar with: R, SPSS, SAS, MiniTab

Advise against using Excel - some techniques not included - some procedures differ in subtle ways and may give answers inconsistent with statistics programs

Stat203

of 13 Fall 2011 - Week 1, Lecture 1 More Helpful Info

 Read lecture notes; make your own study notes

 Read the text ahead <- a little bit EVERY DAY

 Practice! Practice! Practice!

 Collaboration on Assignments is encouraged, but your work must be your own

 Academic integrity is required of all members of the University. Please consult the General Guidelines of the calendar for more details.

 Don't compromise the learning of your fellow students

10 Statistics …

“If the results disagree with informed opinion, do not admit a simple logical interpretation, and do not show up clearly in a graphical presentation, they are probably wrong. There is no magic about numerical methods, and many ways in which they can break down. They are a valuable aid to the interpretation of data, not sausage machines automatically transforming bodies of numbers into scientific fact.”

-- FHC Marriott

Stat203

of 13 Fall 2011 - Week 1, Lecture 1 Video of the Week

Hans Rosling: New Perspectives on the HIV Epidemic Professor, International Health Karolinska Institutet Director, Gapminder Foundation

Why are we watching this? Data presented:  Variables:

o Time (year) o HIV Infections (%, #)

o Income ($ per person) o Region (Country, Continent) Notice:  The impact statistics can have on perception  The importance of graphical presentation  The absence of formulas or numbers Consider:  trying to get this point across without a lot of #s  whether this is convincing or has your mind changed http://www.youtube.com/watch?v=3qRtDnsnSwk

12 Statistical Critique of Hans Rosling:

Confounding

- Causal links for differences are proposed, is that valid?

- Is it possible that there were other reasons for these differences?

Statistical Bias

- did methods of data collection vary over time? Over country?

- is it possible that different countries differ in the way the data is captured?

Variation

- within-country variation is mentioned, but not quantified; some segments of the population may be very different from others

These three terms will be revisited throughout this class and will be critical to ensure they are accounted for when results are interpreted.

Stat203

of 13 Fall 2011 - Week 1, Lecture 1 Reading for Lecture #2:

Chapter 1