| Date: | Mon, 6 Sep 2010 14:45:56 -0400 |
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| Reply-To: | Art@DrKendall.org |
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| Sender: | "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU> |
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| From: | Art Kendall <Art@DrKendall.org> |
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| Organization: | Social Research Consultants |
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| Subject: | Re: Help Creating Clusters |
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| In-Reply-To: | <AANLkTi=NLtsF8PgGEJ1HfvrAYcDwabQG8BvHCTkB2Wfu@mail.gmail.com> |
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when you have 2 nominal level variables you can display continuous
variable on heat maps. See <help>.<br>
<br>
However, collapsing categories can increase noise.<br>
<br>
<big><big><b>A lot depends on the overall goal of your analysis.</b></big></big><br>
Do you have reasons for every case having to be put into the
categories?<br>
<br>
See if using DISCRIMINANT would help with what you are trying to do.<br>
autorecode the variable ALL5 into sequential integers.<br>
Use the 8 large groups as the group variable and consider the other
groups as "ungrouped" for the classification phase of the
DISCRIMINANT. That way the unclassified cases will be assigned to
the group that is the smallest distance from the centroid of one of
the large group.<br>
The classification table will give you info on how distinct the 8
groups are.<br>
<br>
Alternatively, cluster only on the other variables and crosstab the
membership variable with ALL5.<br>
<br>
Art Kendall<br>
Social Research Consultants<br>
<br>
On 9/5/2010 9:54 AM, Amal Daher wrote:
<blockquote
cite="mid:AANLkTi=NLtsF8PgGEJ1HfvrAYcDwabQG8BvHCTkB2Wfu@mail.gmail.com"
type="cite">
<div>Dear Mr. Kendall,</div>
<div> </div>
<div>Many thanks for the reply!!</div>
<div> </div>
<div>Very good suggestion regarding the computation - I just had
to translate the two cases into 1s and 0s using "record into a
different variable" first but it worked, I have them split into
the different 16 segments now (I am only using 4 variables now,
not 5).</div>
<div> </div>
<div>To reduce to 4/6 segments, I will do two things:</div>
<div>- First merge those segments that are too small with the
closest other segment - already that will reduce the segments
significantly. From the 16, eight account for 97% of the sample
so I just combined the other eight with one of the first eight
segments</div>
<div>- As you pointed out, I have other variables in the data set
and need to identify patterns that might allow me to merge
segments</div>
<div> </div>
<div>I will do frequency graphs for the second point of each
segment with the other variables I'll be looking at. Do you know
of a more effective way to go about that? Is there heat maps on
SPSS I can use to clearly visualise patterns?</div>
<div><br>
Would appreciate your advice, and thanks so much again for the
help!</div>
<div> </div>
<div>Amal.<br>
<br>
</div>
<div class="gmail_quote">On Sun, Sep 5, 2010 at 2:28 PM, Art
Kendall <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:Art@drkendall.org">Art@drkendall.org</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="padding-left: 1ex;
margin: 0px 0px 0px 0.8ex; border-left: 1px solid rgb(204,
204, 204);"> You can get a variable that represents the 5
dichotomies by something like this.<br>
<br>
numeric Pattern5(n5).<br>
compute Pattern5= (voice*10**4)+ (data*10**3) +
(content*10**2) + (x*10**1) + (y*10**0).<br>
*note how the exponents decrease. the exponents of 1 and 0
are made explicit for purposes of clarification.<br>
*given the order operations are executed the parentheses are
also technically unnecessary.<br>
<br>
How do you know there should be only 4 to 6 within the 32?<br>
<br>
How do you plan to collapse categories on Pattern5?<br>
Do you have other external variables that you want to use so
that you can collapse segments that are similar on those other
variables?<br>
Do you want to collapse segments where one pattern occurs
frequently and another is relatively rare but differs only on
one of the original 5 dichotomies? Or what?<br>
<br>
What do you mean by a "large" sample? Millions of cases?
Hundreds of thousands?<br>
<br>
On what basis do you want to assign weights to variables in
the collapsing?<br>
<br>
Art Kendall<br>
Social Research Consultants<br>
<br>
On 9/5/2010 5:12 AM, Amal 1 wrote:<br>
<blockquote class="gmail_quote" style="padding-left: 1ex;
margin: 0px 0px 0px 0.8ex; border-left: 1px solid rgb(204,
204, 204);">It’s the first time I use SPSS.<br>
<br>
I need to make an analysis on specific segments.<br>
<br>
I have a very large set of data (results of a sample), and I
want to<br>
define segments based on 5 variables (voice usage, data
usage, Content<br>
usage, etc.)<br>
So I will have about 32 different combinations (~ 2 cases
per<br>
variable). Is there any way I can define those 32
combinations that<br>
faster than having tons of “if statements”?<br>
<br>
What I want to do is define those 32 segments, and then try
to see<br>
similar patterns between them to see which groups I can
combine to<br>
shrink the number of segments to about 4 to 6 maximum.<br>
<br>
Let me know what tools I should be looking at in SPSS cause
I am<br>
really stuck!<br>
<br>
I checked the “direct marketing -> segment my clusters
into segment”<br>
functionality, but it doesn’t allow me to define the
segments the way<br>
I want or even put weights for each of the variables I want
to use.<br>
<br>
Any help is appreciated!!<br>
<br>
Thanks!!<br>
</blockquote>
</blockquote>
</div>
<br>
</blockquote>
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