Psychology 801 – Statistics I Spring 2013
Instructor: Camilo Ortiz, Ph.D.
E-mail: drcamilo.ortiz@gmail.com
Office phone: (516) 299-3754
Class meeting room: PSC Conference Room Website: http://myweb.brooklyn.liu.edu/cortiz/index.htm
Dates: 1/22/13 - 5/2/13. There will be 26 classes.
Time: Tuesdays/Thursdays, 10:30-12:00
Office Hours: Wednesday, 12:00-2:00 or by appointment
Course Description
Psychology 801 is the first part of a two-semester sequence on statistical methods. In this course, we will
review the fundamentals of descriptive and inferential statistics. We will also spend a lot of time learning
how to use the statistical computer program, IBM SPSS (version 20) to put what we learn into practice.
Objectives
1) Better understand the statistical analyses that you read in research studies
2) Increase your readiness to take more advanced courses in statistical methods
3) Identify the appropriate statistical procedure to use for many research questions
4) Feel more confident about using statistical methods to analyze data
5) Carry out several different types of statistical analyses using SPSS
6) Develop your analytic thinking skills
7) Improve your APA writing skills of results sections
Method for Assessing Student Progress & Attainment of Objectives
 Method #1 Twenty-five daily quizzes
 Method #2 Seven SPSS assignments
Method for Evaluation of Student Competency
Foundational
 Ethics: Presence of original ideas and original written work.
 Individual & Cultural Diversity: Demonstration of understanding of individual and cultural
issues in written work and classroom discussion.
 Professional Development: Evidence of responsible treatment of peers and meeting course
responsibilities.
Core Competencies
 Research & Assessment: Understanding of appropriate statistical methods depending on the
research question.
Lifelong Learning
Since the content of the field of psychology significantly changes every ten years or so, each course in the
program exposes students to “ways of knowing.” The method in this course for assessing students’ abilities
to maintain intellectual curiosity about human behavior, culture, etc is their daily quiz work and SPSS
assignments, which demonstrate students’ abilities to think creatively about statistical issues.
Required Textbook
Field, A. (2009). Discovering Statistics Using SPSS. (3rd edition) Sage Publishing.
Required software
SPSS is required to complete many of the assignments. It is installed in the computer lab in Lodge B. You
can also get a free 14 day download of IBM SPSS here:
http://www14.software.ibm.com/download/data/web/en_US/trialprograms/W110742E06714B29.html
You can also get an SPSS grad pack (base version) for about $90, which will allow you to do all of the
assignments for this class.
Pre-requisite
2nd year PsyD student status
An introductory undergraduate course in statistics.
Blackboard
I am slowly adding Blackboard capabilities to this class. This semester, I have set up a discussion group for
stats questions. Just log into blackboard (https://blackboard.liu.edu/webapps/login/) and you will see that I
have started a thread. If a question comes up after class, just ask it! And if you see that someone has asked
a question and you think you know the answer, feel free to answer it! I will of course also answer the
question. You can set it up to get an email when someone has responded to the threat.
Study Groups
I strongly recommend that you form groups of 2-4 people to meet weekly to go over the material. If you
feel a little shaky with the topic, these groups will help you and if you are a strong student, you will learn a
great deal by teaching the material to your classmates.
Academic Integrity
A BREACH OF OUR STANDARDS OF ACADEMIC INTEGRITY CAN RESULT IN A FAILURE IN THIS COURSE AND
EXPULSION FROM THE PROGRAM. IT IS NOT WORTH IT. WHEN IN DOUBT, CONSULT THE STUDENT
HANDBOOK, GRADUATE BULLETIN, AND YOUR PROFESSORS.
From Graduate Bulletin, 2012-2013, page 13: “Plagiarism and cheating are not only serious violations of
the rules, but also may reflect adversely on the student’s reputation as well as on the reputation of the
Campus. Faculty, administrators and the student body share responsibility for academic integrity. A student
in violation of accepted academic procedures may be subject to disciplinary action, up to and including
expulsion from the Campus.” (See Graduate Bulletin for full policy).
Attendance policy
Attendance is not taken for this class. As professionals, you must make your own decisions about how to
spend your time. However, missing a class means missing a daily quiz, for which there are no makeups for
any reason.
Grading Scheme
Twenty-Five Quizzes: At the beginning of every class (except for the first class) you will have a quiz relating
to the main ideas we discussed in the previous class. You will have about 10 minutes to complete these
quizzes. Students arriving at 10:40 or later (according to Camilo’s phone) will not be able to take the quiz
that day. Calculators are not required but may be helpful in some instances. These quizzes are meant to
provide you with consistent feedback throughout the semester. Of the 25 quizzes, I will take your 18
highest scores. Each quiz will be worth 3% of your final grade for a total of 54% of your final grade. There
will be no make-ups of these quizzes for any reason. Questions from previous quizzes can and will be
reused in later quizzes so examine corrections carefully and do not jettison knowledge from your brain just
because you have taken a quiz on it!
Seven SPSS Assignments: You will be required to put what you learn into practice! During the semester,
you will perform statistical analyses that we learn in class with a set of data. If you don’t have your own
data, you may use a set of files that you can download at http://www.sagepub.com/field3e/SPSSdata.htm.
Simpler assignments will each be worth 5% of your final grade, and more complex ones will be worth 10%
of your final grade, for a total of 45%.
A correct (no errors in procedures employed, implementation, interpretation, write-up), complete, welldocumented, and neat assignment receives a score of 4.5/5 (or 9/10 for an assignment worth 10 points).
An assignment that goes beyond the minimum required will receive a higher score. For example, you could
perform an extra analysis or two. Bold any work that you consider “extra” so there is no chance I’ll miss it.
All SPSS assignments must be in APA style and look like Results sections from an APA style manuscript.
One free point just for being you. Awwww!!!
All assignments should be printed double-sided.
Extra Credit: There is no opportunity to earn extra credit. Students who are struggling are strongly urged to
attend office hours on a regular basis, as soon as they notice a problem. Do not wait! Just 15 minutes per
week in office hours typically makes a big difference!
Why does Camilo take off quarter points on quizzes and papers?!?!? Statistical writing is idiosyncratic and
at times bizarre. However, there are specific ways to write things that cannot be deviated from. Often a
single word can completely change the meaning of a sentence or render it incorrect. For example, writing
that a result “approached significance” is incorrect (I’ll explain in class). So there will be times that I will
take off a quarter of a point to alert you to a small but important mistake. This is not meant to irritate you!
Readings
You should do the readings before the class, so that you can ask better questions. The readings should be
done with a computer running SPSS in front of you so that you can try out every step in real time. If it
does not say “optional” next to a reading, you must read it and you may be tested on it.
Homework Problems
At the end of each chapter, there are homework problems (Smart Alex’s Tasks). They are just for you to
practice. These problems are diagnostic tools so that you can see if you do not understand a particular
concept. The best way to use these assignments is to try hard to complete them on your own, and if you
cannot, come to office hours and we can go through them to clear up any misunderstandings.
Late/Make-up Policy
Any work handed in past the deadline (noon on the day the assignment is due) will lose one point
immediately and another point for every 24 hours. If you put a late paper in my mailbox, write the date and
time on it. If you do not, I will assume it got there right before I picked it up.
Accommodation of Disabilities
Students with disabilities who require accommodations for this course must contact the Office of Disability
Support Services at (516) 299-3057 or learningsupport@cwpost.liu.edu.
Scoring Confidentiality
When handing in or emailing assignments, please write the last 4 digits of your student ID number (not
your social security number) on the assignment, instead of your name, to ensure grading fairness.
7 Layers of Stats Hell
Grading Criteria
A
93-100 Total Points
Work is excellent; student not only demonstrates high achievement
but also superior intellectual initiative beyond the objectives of the course; superior test performance;
consistent superior performance across all work and tests.
A90-92.99 Total Points
Work is excellent; student demonstrates either high achievement (by
going beyond the requisites of the course) or surpasses expectations for a student at this level; clearly
demonstrates knowledge and competence beyond course requirements.
B+
87-89.99 Total Points
Work is very good; student demonstrates clear understanding of the
material and work is generally proficient and relatively free of errors; very good test performance.
B
83-86.99 Total Points
Work is acceptable; student has applied requisite understanding of the
material; acceptable test performance.
B80-82.99 Total Points
Work is acceptable but lacking precision or understanding of the
material; below average test performance.
C
73-79.99 Total Points
Work is unsatisfactory due to one or more of the following: failure to
consistently complete course assignments, inconsistent professional quality of written material, erratic in
meeting deadlines, inadequate or incomplete familiarity with key ideas, concepts and knowledge, flawed
written and verbal accounts of information. (Performance below a grade of C in any required course must
be remediated until it is determined that the student has sufficiently mastered the material to be able to
proceed with the curriculum.)
F
72.99 Total Points or Below Work is unacceptable for a graduate student; work errors greatly
exceed those of the class, student has not effectively applied knowledge at this level from readings, class;
poor performance on tests. COURSE MUST BE REPEATED.
INC
Work which, as far as it has progressed, is of B- or higher quality, but is incomplete because of
illness, accident, or other serious extenuating circumstances. All incompletes must be completed before the
end of the next semester or the grade will be automatically changed to an F. The DTC strongly discourages
incompletes. They should not be used to grant extensions without the existence of extraordinary
circumstances.
Class schedule
January 22nd: Introduction & Basic Statistical Concepts
Reading:
Field Chapter 1: Sections 1.5.1.2, (Levels of measurement) 1.5.2, (Measurement error) 1.5.3,
(Validity & reliability) & 1.6.2.2 (Types of variation in statistics)
Handout from my website on Basic Research Methodology Concepts (Aron, A. & Aron E.
(2003). Overview of the logic and language of psychology research. In Statistics for
Psychology. Prentice Hall)
Gould, J. (2008). gradPSYCH Extra: Get real. Feel like an imposter? You're not alone.
http://www.apa.org/monitor/2008/07-08/imposter.aspx
January 24th: Distributions, Measures of Central Tendency, z-scores
Reading:
Field Chapter 1.7.1 through 1.7.4 (Frequency distributions, Skew, Kurtosis, z-scores)
Handout from my website on z scores
Listen:
National Public Radio (NPR) story on Paul Meehl & statistical vs. clinical judgment
http://www.npr.org/features/feature.php?wfId=1584411 (8:48 in length) We will listen in
class as well.
Daily Quiz #1
January 29th: Fitting Statistical Models, Measures of Variability (Residuals, Variance, Standard Deviation),
Degrees of Freedom
Reading:
Field Chapter 1.7.5 (Fitting statistical models) then 2.1 through 2.4.3 (Degrees of freedom)
Manjoo, F. (2013). Space Invaders Why you should never, ever use two spaces after a period. Slate
Magazine.http://www.slate.com/articles/technology/technology/2011/01/space_invaders.single.html
Daily Quiz #2
January 31st: Sampling Distributions, Central Limit Theorem, Standard Error, Confidence Intervals
Reading:
Field Chapter 2.5 through 2.5.2.4 (The standard error, Confidence intervals)
Handout from my website on the standard error
Assignment #1 due today: Complete by hand and submit both Self Tests on page 38 of your text book. You
must show all of your work. (5 points)
Daily Quiz #3
February 5th: Test Statistics, p values, Statistical Significance
Reading:
Field Chapters 2.6 through 2.6.1, (Test statistics, Statistical errors) Chapter 3 (The SPSS
environment)
Articles on my website: Streiner, D. I. (1996). Maintaining standards: Differences between
the Standard Deviation and Standard Error, and when to use each. Canadian Journal of
Psychiatry, 41, 498–502.
Cohen, J. (1994). The earth is round (p < .05). American Psychologist, 49(12), 997-1003.
Haller, H. & Kraus, S. (2002). Misinterpretations of significance: A problem students share
with their teachers? Methods of Psychological Research, 7(1), 1-20.
Listen:
Null-hypothesis Significance Testing: Benign or Malignant? Podcast located at:
http://behaviortherapist.podbean.com/2012/01/08/null-hypothesis-significance-testing-benign-or-malignant/
In this episode, Marc Branch, Ph.D. is interviewed about Null-hypothesis Significance Testing (NHST).
Topics discussed include:
Common misunderstandings about NHST
What p really is
Side effects of NHST
Logical problems with NHST
Reasons NHST remains prevalent despite the many known problems
Alternatives to NHST
Optional:
Watch one or more flash movie tutorials on the book’s website about how to work with SPSS
at http://www.sagepub.com/field3e/SPSSFlashmovieslect.htm
Movie 1: Entering Data
Movie 2: The Syntax Window
Movie 3: The Viewer Window
Movie 4: Exporting SPSS Output to Word (great for writing papers)
Movie 5: Excel
Movie 6: Importing Text
Movie 7: Selecting Cases
Movie 8: Editing Graphs
Assignment #2 due today: With SPSS running in front of you, do everything that the author does in Chapter
3. Also, create variables in SPSS so that you can enter the data in Table 3.1 (page 72). Use the same variables
that are shown in the table, but enter your own numbers so that each of you has different data. Print out
and hand in both the data view and the variable view. (5 points)
Daily Quiz #4
February 7th: Type I & Type II errors, Effect Sizes
Reading:
Field Chapter 2.6.2 (One & two tailed tests) 2.6.3 (Type I and II errors) 2.6.4 (Effect Sizes)
Chapter 4 (Exploring data with graphs)
Chapter 4 should be read in front of a computer running SPSS so you can do exactly what
Field does in the chapter. Just reading it without following along will not be helpful.
Article on my website: Sun, S., Pan, W., & Wang, L. L. (2010). A comprehensive review of
effect size: Reporting and interpreting practices in academic journals in education and
psychology. Journal of Educational Psychology, 102(4), 989-1004. doi: 10.1037/a0019507
Watch:
A very funny and surprisingly helpful cartoon about statistical significance (3 minutes)
http://www.youtube.com/watch?v=ax0tDcFkPic
Daily Quiz #5
February 12th: Statistical Power, Clinical Significance
Reading:
Field Chapter 2.6.5 (Power)
Watch:
Helpful video on power http://www.youtube.com/watch?v=kMYxd6QeAss&feature=related
Download:
G Power Version 3 (A free power program) at www.psycho.uni-duesseldorf.de/abteilungen/aap/gpower3/
Daily Quiz #6
February 14th: V Day No class
February 19th: No class (Monday classes meet, Tuesday classes suspended)
February 21st: Assessment and Treatment of Missing Data and Outliers
Assignment #3 due today: Using your data from the first SPSS assignment, complete “Smart Alex’s” task 1
(not task 2) from page 130. Edit all of the figures so they are easy to read and understand. In other words, do
not just send me the junky looking SPSS versions of these charts. You may need to center certain words,
add color, change the names of variables, etc. These need to be APA manuscript quality figures, so consult
the latest APA publication manual on how to properly format figures. Please cut and paste the charts into a
single Microsoft Word document. Below each figure, write a description (not just a title) of what the figure
shows. For a great tutorial on how to import and edit SPSS figures in Microsoft Word, go to:
http://www.statsmakemecry.com/smmctheblog/2011/2/3/how-to-make-spss-produce-all-tables-in-apaformat-automatica.html 5 points
Optional:
Article on my website: Schlomer, G. L., Bauman, S. & and Card, N. A. (2010). Best practices
for missing data management in counseling psychology. Journal of Counseling Psychology,
57(1), 1-10.
Daily Quiz #7
February 26th: Statistical Assumptions of Parametric Data
Reading:
Chapter 5.1 through 5.5.3 (Exploring statistical assumptions) (Chapter 5 should be read with
SPSS running in front of you)
Daily Quiz #8
February 28th: Correcting Violations of Statistical Assumptions of Parametric Data, Measuring inter-rater
Reliability (Chronbach’s alpha, intraclass correlations)
Reading:
Daily Quiz #9
Chapter 5.6 through 5.6.2 (Exploring statistical assumptions)
March 5th: Correcting Violations of the Statistical Assumptions of Parametric Data: Transformations,
Assumption free Tests, Robust Methods Including Bootstrapping
Reading:
Chapter 5.7 through the end of the chapter (Exploring statistical assumptions)
Daily Quiz #10
March 7th: Covariance, Correlation
Reading:
Chapter 6.1 through 6.4 (Calculating covariance & correlation, CIs for correlation)
SPSS Assignment #4 due today: Using one of the SPSS datasets from the book’s website, making sure the
dataset has at least one categorical variable and a large number of subjects:
1) Create boxplots for at least 2 continuous variables. Describe any outliers you find.
2) Have SPSS compute skewness and kurtosis for at least 2 continuous variables
3) Compute by hand (no need to show work), the zskewness and zkurtosis for each of these variables (and whether
they are statistically significant)
4) Split the file for each of the 2 variables (using the categorical variable) so that you can compute Z-scores of
skewness and kurtosis for subgroups of subjects. For example, you could compute skewness and kurtosis
on the variable “income” for men and for women separately.
5) Use the Kolmogorov-Smirnov (K-S) test to also examine normality for each variable (including each
subgroup). Remember that with large samples, it may not be useful.
6) Find at least 1 variable (possibly from other SPSS datasets from the companion website) that is not
normally distributed. Transform the variable until it appears more normal. It doesn’t have to be perfectly
normal. Describe the process.
7) Write up your results in paragraph format, as if you were writing the results section for a real study, strictly
sticking to APA style. All tables and figures need to be incorporated into the text as if you were writing an
APA style results section. Pay particular attention to how you are supposed to report the different types of
statistics.
Since this SPSS assignment is rather long, leave extra time. 10 points.
Daily Quiz #11
March 12th: NO CLASS-Spring Recess
March 14th: NO CLASS-Spring Recess
March 19th: Orthogonality and Nonorthogonality in Correlation, Partial Correlations
Reading:
Chapter 6.5 through 6.6.2 (Assumptions of r, R2, Partial correlation)
Daily Quiz #12
March 21st: Semipartial Correlation, Suppressor Effects, Factors That Attenuate Correlations
Reading:
Chapter 6.6.3 through end of chapter (Semi-partial correlations, Comparing independent &
dependent rs for statistical significance)
Handout:
How do I Calculate the Statistical Significance of a Single Correlation/Compare Whether Two
Correlations are Significantly Different/Construct Confidence Intervals Around a Correlation?
Daily Quiz #13
March 26th: Multiple Regression Fundamental Concepts
Reading:
Field Chapter 7.1 through 7.2.2 (The method of least squares, Regression weights, Overall fit
of a model))
Daily Quiz #14
March 28th: Measures of Model Fit, Introduction to Multiple Regression
SPSS Assignment #5 due today: Using one (or more) of the SPSS datasets from the book’s website, making
sure the dataset has at least one categorical variable:
1) Compute two Pearson’s correlation, and a point-biserial correlation (rpb). When you report the rpb you
must state which group (e.g. men) was higher on the continuous variable. Just stating the correlation,
doesn’t tell the reader much.
2) Compute and report 95% confidence intervals around every correlation you report.
3) Compute two partial (or semipartial) correlations.
4) As shown on page 191 (and in the handout I will e-mail you), compare correlations from two subgroups
(e.g. men versus women) to each other to see if they are significantly different. Note that the formula for
ZDifference in the book is wrong. Both denominator terms should have -3 in them.
5) Write up your results in paragraph format, strictly sticking to APA style. This assignment is short enough
that tables are probably unnecessary and results should just be reported in the text.
Important! No two students may hand in the same exact variables, although you may work together
10 points
Reading:
Field Chapter 7.2.3 through 7.5.2 Assessing overall model fit, individual regression weights)
Daily Quiz #15
April 2nd: Methods of Regression
Reading:
Field Chapter 7.5.3 through 7.5.3.4
Daily Quiz #16
April 4th Finishing Up Regression (Interpreting the SPSS Output for Regression From Start to Finish)
Reading:
Article on my website: Thompson, (1989). Why won’t stepwise methods die? Measurement
& Evaluation in Counseling & Development, 21, 146-148.
Daily Quiz #17
April 9th: Comparing Two Means (Theory behind Student’s t test)
Reading:
Chapter 9 (Comparing two means), sections 9.3 through 9.4.7
reread Chapter 5, sections 5.6, 5.6.1, and 5.6.2 (the assumption of homogeneity of variance)
Daily Quiz #18
April 11th: Comparing Two Means Part 2 (Student’s t test in Practice, understanding t test as regression)
Reading:
Chapter 9 (Comparing two means), sections 9.5 through the end of chapter 9
Optional
Handout from my website on t tests
Daily Quiz #19
April 16th: Introduction to ANOVA
Reading:
Chapter 10 (ANOVA) (10.1 until and including 10.2.10). Skip 10.2.3 and 10.2.4. Then read
10.5 and 10.7. When you are reading 10.5, stop after the first paragraph on page 390.
Daily Quiz #20
April 18th: A Priori Comparisons & Post hoc Contrasts
Reading:
10.2.11 until end of chapter (skip pages 367, 368, and most of 369) (A priori comparisons &
Post hoc contrasts)
Daily Quiz #21
SPSS Assignment #6 due today: Using any of the data sets on the companion website, compare two means
using the appropriate t test (independent or dependent). For example, you could compare the mean on
some variable for men with the mean on the same variable for women. Alternatively, you could compare the
means of two groups receiving different treatments. Make sure to check and discuss all of the assumptions
of the t test. In addition, compute and report the appropriate confidence intervals and effect size. Once
again, strictly stick to APA style and include (if needed) the appropriate figures or tables, making sure that
they are also in APA style and not just cut and pasted from SPSS. Important! No two students may hand in
the same exact variables, although you may work together. 5 points
April 23rd: Factorial ANOVA
Reading: Chapter 12 (Factorial ANOVA) through 12.2.2
Daily Quiz #22
April 25th: Factorial ANOVA cont.
Reading: Chapter 12 (Factorial ANOVA) (12.2.3 through end of chapter; skip 12.6 and 12.8)
Daily Quiz #23
April 30th: Sphericity in Repeated Measures Designs
Reading:
Daily Quiz #24
Chapter 13.1-13.2.5 (Sphericity)
May 2nd: Repeated Measures Designs
Reading:
Chapter 13.3 - 13.7 (Repeated measures designs) (read 13.8 through the rest of the chapter if
you want a challenge)
Daily Quiz #25
SPSS Assignment #7 due today: Using any of the data sets on the companion website, compare three or
more means using an ANOVA. Make sure to check and discuss all of the assumptions of the ANOVA. In
addition, compute and report the appropriate effect size. Make sure that the ANOVA you run is one that is
statistically significant so that you can follow it up with a priori or post-hoc comparisons. In other words,
don’t just run an ANOVA that is not significant with no comparisons. Once again, strictly stick to APA style
and include the appropriate figures or tables, making sure that they are also in APA style and not just cut and
pasted from SPSS. Important! No two students may hand in the same exact variables, although you may
work together. 5 points
***Bring your ipad or laptop to complete class evaluations***