Date:         Fri, 3 Jul 1998 01:09:09 -0500
Reply-To:     "Nichols, David" <nichols@SPSS.COM>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@UGA.CC.UGA.EDU>
From:         "Nichols, David" <nichols@SPSS.COM>
Subject:      Re: QUERY: estimating the true preferential order of objects
Comments: To: "Jayasinghe, Gayathri" <G.JAYASINGHE@CGNET.COM>

Ties can be handled, and SPSS will do so in Release 6.1.4, but you do
need complete data.
 
David Nichols
Principal Support Statistician and
Manager of Statistical Support
SPSS Inc.
 
>----------
>From:  Jayasinghe, Gayathri[SMTP:G.JAYASINGHE@CGNET.COM]
>Sent:  Thursday, July 02, 1998 6:44 PM
>To:    SPSSX-L@UGA.CC.UGA.EDU
>Subject:       QUERY: estimating the true preferential order of objects
>
>Problem:
>I am planning the analysis of a questionnaire survey in which respondents
>give priority rankings to a selection of objects.  eg,
>
>          Object
> Respondent      type1     type2     type3     type4
>      1                       3                            1              2
>      2                       1             3             2             4
>      3                       2             1
>      4                                      1             1             2
>     .
>     .
>Note: Ties are possible.  Less than the max number of objects may be ranked.
>
>I need to,
>1/ estimate the preferential order of objects overall.
>2/ test whether the preferential order of objects is different between
>different categories of people, for example, between males and females,
>between different age groups..etc
>
>I have just one reference which describes Kendalls coefficient of
>concordance which then goes on to suggest an estimate for preferential order
>of objects  as simply the ranking of the column sums.  But this assumes no
>ties and in the case of incomplete rankings, that each object is ranked by
>an equal number of respondents (ie a balanced design).  In the unbalanced
>case would it be wrong to divide the column sum by the total count of
>respondents giving a rating for this object??
>
>Any references to literature, software, robust methods and /or pointers and
>advice much appreciated.  I do not have access to a good statistical library
>unfortunately, so any direct help would be immediately most useful.
> Statistical software available: SPSS 6.1.4 with Professional and Trends.
> Please reply to
>Gayathree Jayasinghe
>International Irrigation Management Institute
>Email:     g.jayasinghe@cgnet.com
>
>Thanks in advance.
>