The SAS system provides a way of creating and/or accessing a variety of data
sets, with techniques for manipulating the data to obtain output
ranging from simple frequency tables to complex three-dimensional
graphs. SAS software is available from the University of Manitoba
for employees and students; more detailed information regarding
SAS is available from the SAS website.
The goal of the MCHP online SAS tutorial is to provide the new
user with enough knowledge of SAS to translate basic research questions
into SAS code, enabling completion of the research project required
by the Epidemiology
of Health Care course at the University of Manitoba. Additional
"intermediate" training material has been developed for new users
of the MCHP data bases; this documentation
covers arrays, do loops, first/last by-group processing, retain
statements, and how to work with dates. (Complete SAS Institute
manual documentation is available online under Academic Software
References, Vendor Reference Materials, on the
Software Team Resources Page, recognized with University of
Manitoba IP addresses.)
A printable version of the manual is available in pdf format (manual.pdf).
A printable draft is being prepared, as well, of sections of the manual which might
be more appropriately organized into an appendix; for example, all material
related to working with the simulated Manitoba Health data
The MCHP online SAS tutorial is best viewed using at least Version 3 of Netscape
or Internet Explorer, with a minimum setting on an SVGA monitor of
256 colours, 800x600 pixels. It was developed for use with SAS Release
9.1 (Windows 95/98 or Windows NT operating system). In addition to
the usual system Help menu, this version of SAS provides additional
information to licenses under the Help headings of "SAS OnlineDoc"
and "Online Tutor".
As a self-guided tutorial, it is suggested that the user review
the general guidelines and SAS program syntax first. The remaining
material might then be followed sequentially: how to prepare a data
set, how to view the data, how to explore and manipulate the data,
how to add observations and variables to a data set, and how to
process the data. (If the user runs SAS and the browser simultaneously,
example code can be copied from the browser to the Program Editor
window in SAS.)
Several sample data sets are referenced:
- Height/weight - is used throughout for illustrative purposes.
- Simulated clinical - can be created by the user to complete
the questions found at the end of the sections on viewing, exploring,
manipulating, adding variables and observations, and processingthe
data (with links to how the program, log, and output should look).
- Simulated Manitoba Health - the data set used by students
of the Epidemiology of Health Care course to complete the required
assignments, only obtainable from MCHP, not from this tutorial.
Additional questions are included
here, for use with this data set, complete with links to the program,
log, and output.
SAS has improved its interface to the point where a lot of analysis can be
simply and quickly carried out using menus, examples of which are
provided in the alternatives to programming
section. It is often desirable, however, for users to have a basic
understanding of SAS programming. Knowledge of SAS programming facilitates
not only spotting some of the pitfalls inherent in processing data,
but also maintaining more complete documentation of all the steps
required to produce any given output. It is all too frequently necessary,
in the course of carrying out research, to reproduce results which
may have required a complex series of data processing steps.
It is important to recognize that there is often no one "right" way of
obtaining accurate results. For simplification and continuity, this document reflects
one style of writing SAS code. There are other more or less efficient ways of
constructing SAS code, however, all of which may produce identical results.
Where alternatives exist for generating results, a legitimate, and often
preferred, choice is code that the user understands.
Resources, References and Acknowledgments