SDA 4.0 Documentation for UPDATES
updates - Changes to SDA since Version 3.5
This document summarizes the differences between Version 3.5 and
the subsequent versions.
- First there is a summary of changes by SDA version
(with links to the next section).
- That summary is followed by a description of the
changes by category.
SUMMARY OF CHANGES BY SDA VERSION
- Version 3.6 (only limited distribution)
- Version 4.0
- Version 4.0.1
- Version 4.0.2
CHANGES BY CATEGORY
CHANGES TO THE INTERFACE (Version 4.0 and later)
- In Version 4.0:
- The user interface was substantially modified in Version
4.0, providing a more modern look with rich, dynamic
- This also allows for the simplification of the interface for
beginning users by hiding more advanced options
until they're needed.
In Version 4.0.1:
- A question mark now indicates that
online help is available by clicking on the
question mark. In previous versions of SDA, the online help was
accessed by clicking on the name of the option -- a mechanism
that was not clear to all users.
In Version 4.0.2:
- Drag and drop from variable tree to input text
You can drag and drop a variable from the variable tree to an
input field on a form. (Note that although the variables in the
tree include both the variable name and the label, only the
variable name will be "dropped" into the input
In addition to "drag and drop," however, the procedure of
clicking on a variable to transfer it to the "Selected" box, and
then clicking a button to transfer the variable to the
appropriate input field continues to function as in previous
Right-click on variable tree to view variable
You can right-click on a variable in the tree
to bring up a context menu where you can click on View
variable to view a description of the variable's
This is a shortcut for the procedure of first selecting a
variable to put it in the "Selected" box and then clicking on the
- In Version 4.0.1:
The Version 4.0 interface was modified to include an
accessibility interface that was compliant with Section
508. There is a checkbox at the top of the option screen to
enter that mode.
In Version 3.6:
The former version 3 "Classic Interface" was updated into an SDA
interface that was easier for screen readers to interpret. This
revised accessibility interface was intended
to be compliant with requirements to make all SDA software
accessible to those with disabilities. However, version 4.0.1
provides a more complete solution for the issue of accessibility.
RE-RUNNING (BOOKMARKABLE) ANALYSIS OUTPUT
NEW SDA MANAGER WEB APPLICATION (Version 4.0 and later)
- A new SDA Manager web application is part of the SDA
distribution package for Version 4.0 and later. The SDA Manager
consolidates all of the management functions
for an SDA archive into one web interface. And all of the
configuration information for an SDA archive is consolidated into
one location -- a MySQL database. Previously, the management
functions were handled by separate applications, and the
configuration information was dispersed in various files across
- The SDA Manager webapp also supports the configuration of
personal user workspaces. These user
workspaces enable analysts to create and store recoded and
computed variables in their own private storage areas.
- The SDA Manager also allows an archive manager to easily
configure dataset-level access control for
specifying which users can access which datasets.
CHANGES TO ANALYSIS PROGRAMS (after Version 3.5)
MEANS (in Version 3.6 and later)
Calculate a median for each cell
An option was added to calculate and display the median of the
dependent variable, in addition to the mean. If there is a very
large number of cases and table cells, there may not be enough
memory to calculate the exact median for all the cells of the
table. In that case an estimate of the median, called the
remedian, will be computed for some of the cells. An
asterisk next to the median statistic indicates that it was
estimated by the remedian.
LOGIT (in Version 3.6 and later)
Contribution to probability of '1' rather than '0'
An option was added to convert the logit or probit coefficients
to the scale of a probability, to show how much each independent
variable contributes to an increase in the probability that the
dependent variable is predicted to be '1' rather than '0'.
VIEW/DESCRIBE (in Version 4.0.2)
Bars to show relative frequencies
When a frequency distribution is displayed (for variables with
256 categories or fewer), each category is now displayed with a
horizontal bar to show the relative size of
the percent of cases falling into each category.
CHANGES TO THE UNDERLYING ARCHITECTURE
SDA versions 4.0 and later have converted completely
from CGI to Java servlets for the web user interface.
(The previous SDA interface was a blend of CGI and servlet-based
components.) For an archivist who is setting up an SDA archive,
the installation procedure is simplified. The coordination of
CGI and servlet-based components -- which can be tricky to
configure -- is no longer necessary. Also, SDA 4.x requires ONLY
a servlet container (Tomcat) to run. An additional web server --
Apache or IIS -- is no longer required (since CGI is no longer
Upgrading from SDA Version 3.5 (or 3.6)
What does this mean for organizations that already have SDA
archives? What changes in the new SDA version -- and what
doesn't? Many of the pieces of the current SDA architecture
remain the same as before. In particular, the SDA assets that
organizations have developed -- such as SDA datsets, codebooks,
etc. -- are fully compatible with SDA 4.x.
The things that DO NOT CHANGE in the
new architecture include:
- The SDA dataset format
- The SDA codebook format
SDA metadata syntax (DDL)
- All the non-CGI SDA
programs (analysis programs, codebook creation program,
The things that DO CHANGE are:
- The CGI programs (hsda, hsda2, etc.) are
completely replaced by a servlet-based web user interface.
- The configuration information that was
previously stored in HARC files is now stored in a MySQL
database. (However, a simple procedure,
is provided in the SDA Manager to import the information from
existing HARC files into the database.)
CSM, UC Berkeley/ISA
September 5, 2017