STAT6097 Outline - University of Southampton

Diploma/MSc in Official Statistics
Professional Development Programme
STAT 6097 – Compensating for Non-Response
Outline Programme
Building 39, Room 2015, Southampton
Objectives
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To provide students with an understanding of the sources and nature of nonresponse in surveys and its potential effects on estimation.
To provide students with an understanding of alternative weighting methods used
to compensate for the effects of unit non-response.
To provide students with an understanding of alternative methods to compensate
for the effects of item non-response, with a focus on imputation methods.
To enable students to design a strategy involving weighting and/or imputation for
dealing with non-response in a particular survey.
Prior Background Assumed
STAT6093 Survey Sampling is a pre-requisite and it will be assumed that students
understand the basic principles of estimating finite population parameters from sample
data. Some methods to be discussed will involve the application of linear and logistic
regression, so some familiarity with regression to the level of STAT6095 Regression
Modelling will be assumed.
Learning Outcomes
Students will achieve an understanding of:
 the sources, nature and effects of non-response
 the main approaches to weighting for unit non-response
 the main approaches to imputation for item non-response
 how to choose between alternative weighting or imputation methods for a
particular survey
Syllabus
Types of non-response
Response rates
Reasons for non-response
Prevention of non-response
Weighting for unequal selection probabilities
Sample-based weighting
Population-based weighting
Calibration weighting methods
Bias and variance properties of weighting methods
Weight truncation and standardisation
Designing a weighting strategy
Non-respondent sub-sampling and substitution
Approaches to item non-response
Imputation methods
Bias and variance properties of imputation
Variance estimation in the presence of imputation
Designing an imputation strategy
Modelling approaches to missing data
Introductory Reading in Context of UK Government
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Elliot D (1999) Report of the Task Force on Weighting and Estimation. GSS
Methodology Series No 16.
Elliot D (1997) Software to weight and gross survey data. GSS Methodology
Series No 1.
Report of the Task Force on Imputation (1997). GSS Methodology Series No 3.
Each of these three reports may be downloaded from
http://www.ons.gov.uk/ons/guide-method/method-quality/specific/gss-methodologyseries/index.html
Introductory Reading on Methods
Lehtonen R and Pahkinen EJ (1996) Practical Methods for Design and Analysis of
Complex Surveys. Second Edition, Chichester: Wiley, Chapter 4.
Lohr S L (2010) Sampling: Design and Analysis. 2nd Ed. Brookes-Cole, Chapter 8.
References for Course
Bethlehem J, Cobben F and Schouten B (2011) Handbook of Nonresponse in
Household Surveys. Hoboken: Wiley. [wide-ranging overview. Chapter 8 on weighting
and Chapter 14 on item nonresponse are particularly relevant].
Cox BG et al (1995) Business Survey Methods. New York: Wiley.
[Chapters 22 and 25 provide good descriptions of imputation and weighting methods,
respectively, for business surveys.]
Groves R, Dillman DA, Eltinge JL and Little RJA (2002) Survey Non-Response. New
York: Wiley.
[contains introductory chapter on weighting by Bethlehem (ch.18) and some useful
chapters on new developments in imputation, especially chapters 20-22.]
Lessler JT and Kalsbeek WD (1992) Non-Sampling Error in Surveys. New York: Wiley.
[Chapter 8 contains fairly compressed accounts of weighting (pages 192-199) and
imputation (pages 210-229)]
Little RJA and Rubin DB (2002) Statistical Analysis with Missing Data, 2nd Ed. New York:
Wiley.
[Chapter 3 provides a brief account of weighting. Chapter 4 contains slightly more on
imputation.]
Särndal, C-E and Lundström, S (2005) Estimation in Surveys with Nonresponse.
Chichester: Wiley.
[Developed from a ‘Current Best Methods’ manual at Statistics Sweden. It has good
coverage of both weighting and imputation, with an emphasis on putting into common
calibration framework. This is probably the most useful single text.]
Blackboard Site
All students are automatically enrolled on “STAT6097-28308-14-15: 14-15Compensating for Non-Response-28308” blackboard site. If you do not have access
to the site, please let your tutor know so that she can enrol you. There is also a
discussion board on Blackboard so that you can communicate with your fellow students.
To submit an electronic version of the coursework assignment for the 'Turnitin'
plagiarism software, you must access the specific module ‘STAT6097-28308-14-15: 1415-Compensating for Non-Response-28308’ on Blackboard. Once you locate the
specific module, you need to upload the assignment through the 'Assignments' folder
according to the instructions listed below. Only students submitting coursework
assignments will gain access to this site. If you don’t have access to the site, please let
your tutor know.
NOTE: the uploading of an electronic version of the coursework assignment does
NOT replace the two hard-copies of the assignment that are to be sent to the
MOffStat administrator using the coursework hand-in form available at:
http://www.southampton.ac.uk/
demography/postgraduate/taught_courses/msc_official_statistics.page?
Instructions for uploading assignments:
To submit coursework electronically via the TurnitinUK plagiarism device, login to the
Blackboard unit for this module and select the Assignments link from the left-hand menu.
Find the 'assignment' and click View/Complete. There will be a series of screens to
complete, and full instructions. Please note the following points:
1. During the submission process you will see a receipt screen confirming that your
assignment has been submitted. This will show the title of your paper and will also
provide a Paper ID. You should make a note of this Paper ID for future reference in case
of any problems.
2. Following your submission through Blackboard you will receive an email confirmation
that your coursework has been received. This usually takes about an hour but may take
up to 24 hours depending on how busy the system is. You should retain a copy of this
email which will act as a receipt for your electronic submission. If you do not receive this
email then you should contact the module coordinator as soon as possible.
Assessment
The assessment will be by coursework involving two questions. The first question will
require you to perform various weighting schemes to estimate the population mean for a
specified sample. The second question will be about imputation. The deadline for
submission of the coursework is Tuesday, 6th January, 2015 with the postmark required
by the preceding Monday.
Please send 2 hard copies of the assignment to the MOffStat Administration. The
address is:
Claire Woodley
University of Southampton
Building 58, Room 2101
Highfield, Southampton
SO17 1JB
Students who fail to meet the deadline will receive a 5% reduction in their mark for every
working day up to 5 working days. After 6 working days, the standard policy is to award
zero for the coursework assignment.
Procedure for coursework extensions
If students want to request an extension, they must have medical or personal
circumstances to justify the late submission of assessed coursework (medical evidence
must be substantiated by a doctor's note). They should initially fill out a coursework
extension request form available at the above website and send it to their Personal Tutor,
Dr Solange Correa-Onel, who will, where appropriate, agree to the extension of the
deadline after discussion with the module co-ordinator and examination officer. Under no
circumstances will extensions be allowed beyond a period of two weeks.
Resit arrangements
No mark below 25% is allowed for any module in the programme. All students receiving
below the minimum mark will have to resit the module according to School of Social
Sciences policy.
Academic integrity
The University places the highest importance on the maintenance of academic integrity
in the conduct of its affairs, and the Academic Integrity Statement for Students can be
found in the University Calendar available online at http://www.calendar.soton.ac.uk/
sectionIV/academic-integrity-statement.html. Please familiarise yourself with what is
expected of you in this regard by reading through this statement. Your attention is drawn
particularly to Appendix 1, which outlines those things which you must seek to avoid,
including cheating and plagiarism. A very useful set of interactive guides is available at
http://www.studyskills.soton.ac.uk. These aim to help you gain a better understanding of
academic integrity and develop your skills so that your assessed work does not
accidentally plagiarise the work of others.
You must take particular care in using sources in essays and in your dissertation.
Remember that plagiarism includes not only verbatim copying but also direct
paraphrasing of a source. Verbatim quotes from a source should always be in quotation
marks, with the source indicated, and should be used only occasionally in an essay or
other report. Detailed advice on appropriate referencing in essays and dissertations is
given in the Department of Social Statistics “Guidelines on writing essays” and there is
an online guide to referencing at http://library.soton.ac.uk/socialstats/referencing .
Students are encouraged to discuss and exchange ideas, since this is an important part
of the educational process. However, it is not acceptable that you read and gain ideas
for your coursework from another student’s finished work. Copying includes using
another student's computer program, output or graphics. If academic integrity is deemed
to have been breached, there are a range of penalties that may be applied.
If you are unsure about what is and is not permitted, ask - we will be happy to explain
and discuss.
Troubleshooting
Please get in touch with your personal tutor, Dr Solange Correa-Onel, should any
difficulties arise with this module.
Outline Programme
Monday 24 November 2014
10.00-10.10 Welcome and introduction to course
10.10-11.10 Introduction to non-response
11.10-11.30 Break
11.30-13.00 Introduction to weighting
13.00-14.00 Break
14.00-15.20 Sample-based weighting
Exercise 1
15.20-15.40 Break
15.40-17.00 Population-based weighting
Exercise 2
Tuesday 25 November
09.30–10.50 Using models to construct weights
Calibration methods 1
10.50-11.10 Break
11.10-13.00 Calibration methods 2
Exercise 3
13.00-14.00 Break
14.00-15.30 Using weights
15.30-15.50 Break
15.50-16.50 Exercise 4 (computer-based)
Wednesday 26 November
09.30–10.50 Dealing with item non-response
Imputation methods
Exercise 5
10.50-11.10 Break
11.10-13.00 Review of exercise
Properties of imputation methods
13.00-14.00 Break
14.00-15.20 Multiple imputation
15.20-15.40 Break
15.40-17.00 Edit and imputation
Thursday 27 November
09.30-10.50 Statistical modelling methods I
10.50-11.10 Break
11.10-13.00 Statistical modelling methods II
13.00-14.00 Break
14.00-15.30 Exercise 6 (computer workshop on imputation)
15.30-15.50 Break
15.50-17.00 Private study
Friday 28 November
09.30-10.50 Some developments in non-response
10.50-11.10 Break
11.10-12.30 Discussion of coursework, Q&A session, review and evaluation of course

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