A Description of ASSOC
Yu Xie, University of Michigan

What is ASSOC?

ASSOC is a program for the analysis of association tables. The original code was first developed by Leo Goodman and his former students at the University of Chicago and then made user-friendly by Clifford C. Clogg in a computer program called ANOASC for a wider distribution. It was later modified by James W. Shockey in January, 1983. Several modifications were made by Ruud Luijkx in 1985 and 1986. First PC Implementation was in October 1986 (by Michael Massagli). The latest update (that I know of) was made by Ruud Luijkx in December, 1988. The ASSOC program deals with K separate I-by-J cross-tables and estimates Models corresponding to those in Goodman's 1979 JASA-Paper - Generalizations of both Model I and Model II are available.

The following input cards are required (each card is one line)

1. (A60) Title for run
2. (10I2) Input/Output information -- Place a 1 in :
Column 2 to suppress observed, expected counts and std.
residuals
Column 4 to suppress observed odds-ratios
Column 6 to suppress expected odds-ratios
Column 8 to suppress parameter estimates
Column 10 for Model II calculations (otherwise Model I
used)
Column 12 to suppress iteration detail
Column 14 if start tables are to be input
Column 16
If no specific diagonal parameters are to be included
type in Column 16 zero. Otherwise:
1 for free diagonals, i.e. each diagonal cell in every
group has one diagonal parameter (quasi- models);
2 for Group Specific Diagonal Parameters, i.e. one
diagonal parameter for each group (table)
3 for Category Specific Diagonal Parameters, i.e. one
diagonal parameter for each diagonal cell for all
groups (same density in the same diagonal cell in each
table).
4 Combination of 2 and 3: Group and Category Specific
Effects
5 One diagonal parameter for all diagonal cells

Column 18 to suppress the printing of Row and Column
Parameters

Column 20 to suppress the printing of Alpha- and Beta-
Ratios, or Mus, Nus and Mu- and Nu-Differences.

3. (2I2,I3,F8.7,I4,F4.3) #Rows, #Cols, #Groups,
Tolerance(def=.01) Iterations (def=100), Constant to be
added to all frequencies (def=.0)

4. Input Format for data -- e.g. any valid Fortran format;
examples: (8F6.0),(8X,7F5.3), or FREE

5. Name of file on which the data are stored in the above
Format

6. Input start tables (necessary only If column 14 of card #2
is 1) -- In the same Format as was used for the data,
place a 1 in those cells to be included and a 0 (zero) in
those to be ignored or excluded, i.e. treated as
structural zeroes.

7. (15I2) Model selection : Place a 1 in :
Column 2 If Null Conditional Association (Conditional
Independence)
Column 4 If Homogeneous Conditional Uniform Association
Column 6 If Heterogeneous Conditional Uniform Association
Column 8 If Homogeneous Conditional Row-Effects
Column 10 If Homogeneous Conditional Column Effects
Column 12 If Simple Heterogeneous Row Effects
Column 14 If Simple Heterogeneous Column Effects
Column 16 If Heterogeneous Row Effects
Column 18 If Heterogeneous Column Effects
Column 20 If Homogeneous Row and Column Effects
Column 22 If Heterogeneous Row, Homogeneous Column
Column 24 If Heterogeneous Column, Homogeneous Row
Column 26 If Heterogeneous Row and Column
Column 28 If Homogeneous Equal Row and Column Scalings
Column 30 If Heterogeneous Equal Row and Column Scalings

Example

(1) We store the following data (from Clogg 1982, AJS, Table 5)
in file "abort2.dat":

44 11 38 62
59 41 147 293
23 11 13 27
27 8 16 27
258 57 105 110

(2) We edit a control file "abort2.ctl" as:

Replicating Clogg (1982), Data from Table 5
0 0 0 0 1 1 0 0 0 0
5 4 1
FREE
abort2.dat
1 0 0 0 0 0 0 0 0 0 0 0 1 0 0


In UNIX, enter:

assoc abort2.ctl abort2.dat abort2.log

Note: three arguments follow program "assoc": (1) control file,
(2) data file, and (3) output file

The following files are provided to you free of charge. You
may copy, distribute, and use these files for education and
research purposes.

assoc.f Fortran source code
abort2.ctl A test program
abort2.dat Data on abortion attitude
abort2.log Output file from abort2.ctl
abortion.ctl GLIM control file for comparison
abortion.log GLIM output file from abortion.ctl