Help, Chi Square Test for Independence

[Donna Daniels]

Hello Everyone,

I would like to thank all those who helped me run the Chi Square Test.
Now I have another issue. After running the Crosstab, SPSS gave me an
individual table for each possible combination which gave me 161 tables.
How do I create a 7 X 23 table? Please read the original questions below:

> Please forgive my previous email. I pasted the description of what I
> am trying to do from my dissertation proposal. The test is the Chi
> Square Test for Independence. The variables are the type of drug which
> includes marijuana, cocaine (powdered), crack cocaine, ecstasy,
> methamphetamine, the illegal use of prescription drugs, and polydrug
> use; the other variable is the crime which is the dependent variable
> in this study. There are 23 different crimes used in this study.
> Please review the additional information below:
>
> The researcher will conduct the Chi-Square test to verify frequencies
> of specific drug use and specific crimes committed. Crime data is
> recorded in a database as required by the Federal Bureau of
> Investigation under the Uniform Crime Reporting Program and the
> Incident Based Reporting System. The counts from the databases are
> considered expected counts while the participant responses to the
> survey questions are considered actual counts.
>
> The data collected based on the type of drug has nominal values.
> Therefore, the Chi-Square test will be helpful in determining the
> actual count of marijuana, cocaine (powder), crack cocaine, ecstasy,
> methamphetamine, prescription drugs, and polydrug use in specific
> crimes. “The statistic is the difference between the observed count
> and the expected count in each cell, divided by the expected count,
> summed over all cells” (Aczel & Sounderpandian, 2006, pp. 680-681).
>
> The researcher will gather the data based on police reports submitted
> to the Uniform Crime Reporting System as required by the Federal
> Bureau of Investigation (FBI). These are the expected counts on the
> contingency tables. Once the numbers are entered for all crimes
> committed, the researcher will then enter the numbers from the data
> gathered during the offender survey. The table for Crime Categories is
> found on page 113, Table 13. The purpose for conducting the Chi-Square
> Distribution is to determine if specific drug use leads to significant
> occurrences of specific crimes.
>
> The researcher will first conduct a Chi-Square Test for Independence.
> To do this, a contingency table will be used. There are two
> classifications in the contingency table for this study: Drug Type and
> Crime Category. The hypothesis test for independence is:
>
> H0: The variables named drug type and crime category are independent
> of each other.
> H1: The variables named drug type and crime category are not independent.
>
> If the computed value of the chi square statistic is greater than the
> critical value, the null hypothesis is rejected.
>
> I hope this clarifies anyone's questions.

Thank you in advance for your assistance.

Warm regards,

Donna Daniels

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

[David Hitchin]

Quoting Donna Daniels <[hidden email]>:

> Hello Everyone,
>
> I would like to thank all those who helped me run the Chi Square Test.
> Now I have another issue. After running the Crosstab, SPSS gave me
> an individual table for each possible combination which gave me 161
> tables.
> How do I create a 7 X 23 table?
>
I assume that your data values consist of a variable with a heading
something like "drug" containing values between 1 and 7, a variable
"crime" with values between 1 and 23 (so that you have 161 combinations
altogether) and a variable which, for each combination, is the number of
occurences of each crime associated with each drug, call this variable
"count".

It sounds as though you have set up your crosstab by filling the three
boxes of the cross-tab specification with "crime", "drug" and "count",
which would give the result you have described.

What you need to do is first go to the "Data" tab at the top of the data
sheet, open the menu and go down to "Weight data". Open this box, click
the "weight cases by" button, and then move "count" into the "frequency
variable" box, and click "OK".

Now go to "Analyse", "Descriptive statistics" and select "Crosstabs".
Put "Crime" into the Rows box, "Drugs" into the Columns box, and click
OK. This should produce the table that you want.

Before producing tables you have the options of clicking on the
"statistics" box to choose the statistics that you need, and the "Cells"
box to choose what will appear in the cells of the table. You can print
Observed frequencies, expected frequencies, row and column percentages.
All of these might be useful to you, and when you have a little practice
at reading tables, the Adjusted Standardized Residuals can tell you a lot.

DON'T ask for any more than one of these on any crosstab !!!  If you do,
then each cell of the table will contain several numbers, making it very
 difficult to see what is going on, and as the table is intended to help
you interpret the results you need the presentation as clear as
possible. A table with 161 cells won't be that easy anyway.

If you want several of these quantities, then just select ONE of the
options for each crosstab that you do. Each will produce ONE table at a
time.

David Hitchin

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

[Mark A Davenport MADAVENP]

First and foremost let me say that I am not in any way associated with the
administration of the SPSS list and do not speak for the list.  I am a
long time poster; a researcher, and a stats teacher that finds the
collegiality and expertise on this site second to none.

I've been an active user of this site for many years and have noticed that
every few years we start to see an increase in the 'Please do my homework
for me' type of question.  This is a great list supported by a large cast
with hundreds, maybe even thousands of years of collective experience.
Students have always been welcome on this site and I hope that never
changes.  They provide many challenging questions and offer great insight
into the student experience.  However, please at least TRY to run a
procedure before you ask list members how to run it and interpret it for
you.  The recent question about how to run and interpret regression was an
obvious case of someone too lazy to pick up a book or do a google search.
There is a library of books dedicated to the subject of regression, not to
mention the even larger set of texts that have chapters dedicated to the
topic.  A branch of that library contains some great books on how to run
and interpret regression using SPSS.  The UCLA stats site has
step-by-step- instructions, if you can be bothered to do a google search.

So, students, please don't cheapen your learning experience by asking
others to do your research for you.  If you give a problem that 'old
college try' and get stuck, by all means, we are here to help as much as
we can.  All we ask is that you try to help yourself first.

Signed,

A concerned teacher

***************************************************************************************************************************************************************
Mark A. Davenport Ph.D.
Senior Research Analyst
Office of Institutional Research
The University of North Carolina at Greensboro
336.256.0395
[hidden email]

'An approximate answer to the right question is worth a good deal more
than an exact answer to an approximate question.' --a paraphrase of J. W.
Tukey (1962)

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

[Adam B. Troy-2]

I would also recommend the following site, which is one of the best I've
seen for the introductory or intermediate student user.

http://core.ecu.edu/psyc/wuenschk/SPSS.htm


______________________
Adam B. Troy, Ph.D.
Director of Research
GoalQuest
Enrollment and Retention Services Divisions


-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of
Mark A Davenport MADAVENP
Sent: Thursday, March 13, 2008 9:47 AM
To: [hidden email]
Subject: A request of student users of the SPSS list

First and foremost let me say that I am not in any way associated with the
administration of the SPSS list and do not speak for the list.  I am a
long time poster; a researcher, and a stats teacher that finds the
collegiality and expertise on this site second to none.

I've been an active user of this site for many years and have noticed that
every few years we start to see an increase in the 'Please do my homework
for me' type of question.  This is a great list supported by a large cast
with hundreds, maybe even thousands of years of collective experience.
Students have always been welcome on this site and I hope that never
changes.  They provide many challenging questions and offer great insight
into the student experience.  However, please at least TRY to run a
procedure before you ask list members how to run it and interpret it for
you.  The recent question about how to run and interpret regression was an
obvious case of someone too lazy to pick up a book or do a google search.
There is a library of books dedicated to the subject of regression, not to
mention the even larger set of texts that have chapters dedicated to the
topic.  A branch of that library contains some great books on how to run
and interpret regression using SPSS.  The UCLA stats site has
step-by-step- instructions, if you can be bothered to do a google search.

So, students, please don't cheapen your learning experience by asking
others to do your research for you.  If you give a problem that 'old
college try' and get stuck, by all means, we are here to help as much as
we can.  All we ask is that you try to help yourself first.

Signed,

A concerned teacher

****************************************************************************
****************************************************************************
*******
Mark A. Davenport Ph.D.
Senior Research Analyst
Office of Institutional Research
The University of North Carolina at Greensboro
336.256.0395
[hidden email]

'An approximate answer to the right question is worth a good deal more
than an exact answer to an approximate question.' --a paraphrase of J. W.
Tukey (1962)

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD