STA114/MTH136: Statistics

Lec: Old Chem 116 Lab: Teer 106
Mon & Wed 2:50-4:05pm Tue 1:15-2:30pm or 2:50-4:05pm
Prof:Robert L. Wolpert TA:Yiwen Zhu, Kai Mao
Office: Old Chem 211c, 684-3275 Old Chem 211a, 684-5884
OH:Wed 1:30-2:30pm Tue 6-9pm
Mon & Wed 4:05-4:20pm (in classroom)

Home Page Syllabus PDF Formulas Data


An introduction to the concepts, theories and methods of statistical inference. We discuss both the ideas and methods of modern Bayesian statistical science as well as the classical methods based on sampling theory. Statistics is a vast field, and a first one-semester course can offer only a brief introduction, with a deeper look at a few key ideas. The goal of this course is to provide such an introduction and to illustrate through examples how Statistics serves as the foundation for all scientific reasoning and inference amid uncertainty.

Statistical inference is like probability theory, only backwards. In probability we start with a distribution (say, the normal with specified mean μ and variance σ2) and predict features of future observations x=(x1, x2,..., xn); in statistics we observe the data x and then try to guess the distribution (or just the parameters) that generated them.

Statistical modeling and inference depend on the mathematical theory of probability, and solving practical problems usually requires integration or optimization in several dimensions. Thus this course requires a solid mathematical background (calculus and linear algebra at the level of MTH 103 and at least co-registration in MTH 104, or MTH 105) and proficiency in calculus-based probability theory at the level of MTH 135/STA 104, or STA 213. Students without strong preparation in these will need to invest significant additional time to fill in the gaps. The course text is Morris DeGroot & Mark Schervish, Probability and Statistics (3rd edn). All class materials are distributed on-line via the web; for example, you may view homework assignments (and sometimes class notes) on the Syllabus. Blackboard is used only to report scores from homeworks and examinations.

Homework Assignments

The only way to learn statistics is to solve problems (or, in Sophocles' words, One must learn by doing the thing; for though you think you know it, you have no certainty until you try). Weekly problem sets are assigned through the on-line syllabus. Homeworks are collected at the start of each Wednesday class (so I can answer questions about them in class) and are returned at the following Tuesday Lab Session, after which solutions will be posted on the web. Until solutions are posted, late homeworks are accepted but are penalized 10% per day. The two lowest homework scores will be dropped.

You may work with other students on the homework problems, but you must (a) acknowledge the collaboration in writing on your homework and (b) write up yor final answers independently: copying homework solutions is not allowed. You are encouraged to ask me or the TA for help on your homework, after you have tried to solve the problems on your own. Questions about homework scores should first be addressed to the TA.

HELP is available! The TA and I both have office-hours (see above). In addition, the Department of Statistical Science maintains an open Help Session every Sun-Thu in the Statistical Education and Consulting Center, located in room 211a Old Chem, where a statistics graduate student will be happy to help you (detailed times and staffing are listed on the SECC website). There may also be grad students from other departments, helping students in the introductory statistics courses--- be sure to find a Duke Statistical Science grad student (they're listed in steel blue on the TA Schedule.).


In-class Midterm Exams and Final Exam are all closed-book. You may bring one 8½"×11" sheet of paper to each exam with anything you want written on it; the exam will include this sheet of common pdf and pmf formulas. You may (and probably should) bring to each exam a calculator capable of computing exponentials, powers, and factorials (no laptops or netbooks, however). Questions about exam scores should be taken up with the Professor. As an aid to study, here are some past exams:
Spring 2009: 1st Midterm 2nd Midterm Final Exam


Course grades are based on two in-class Midterm Exams (20% each), ten weekly Homework assignments (25% total), and a cumulative Final Exam (35%). Late homeworks are penalized, and missed homeworks receive zero scores, but each student's two lowest homework scores are dropped. Histograms and summary statistics of midterm and final exam scores will be added to the syllabus web page. Brief in-class quizzes will be added if needed. Each student's current average and course standing are available from the instructor at any time.

Academic Integrity

Cheating on exams, plagiarism on homeworks and projects, lying about an illness or absence and other forms of academic dishonesty are a breach of trust with classmates and faculty, and will not be tolerated. They also violate Duke's Community Standard and will be referred to the Office of Judicial Affairs (OJA).

Excused Absence

Students who miss tests or assignments due to a scheduled varsity athletic trip or religious holiday should submit an on-line NOVAP or RHoliday form, respectively, at least a week ahead of time and meet with me to arrange to make up the missed work (often before the scheduled event).

Those with a personal emergency or bereavement should seek a Dean's Excuse; check with your academic dean for details, and see me as soon as possible after your return to schedule make-up work. Dean's Excuses are not issued for short-term incapicating illness; if you are too ill to complete an assignment or attend an examination, just tell me about it as soon as you can using the on-line Illness Form (there seems to be a separate form for grad. & prof. students), and see me when you feel better (before the next class if possible) to make arrangements to make up the missed work. Note that the Community Standard sanctions apply for abuse of this procedure.

No excuse is needed simply for missing class, only for missed assignments and examinations. Class attendence isn't required, but midterm and final exams will cover material presented in class that may not be covered in the text or homework assignments.