percentile scores

[Humphrey Paulie]

Dear everyone,
  How can I get percentile scores for each case who has taken a reading test in a population of 10000?
  I have got their total raw scores but I want percentiles which show thier performance relative to the performance of others?
  Best
  Humphrey



---------------------------------
Do you Yahoo!?
 Next-gen email? Have it all with the  all-new Yahoo! Mail Beta.

[Marks, Jim]

Use RANK:

** not tested.

RANK raw_score /ntiles(100) into pctile.


--jim

-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of
Humphrey
Sent: Wednesday, July 12, 2006 4:12 AM
To: [hidden email]
Subject: percentile scores

Dear everyone,
  How can I get percentile scores for each case who has taken a reading
test in a population of 10000?
  I have got their total raw scores but I want percentiles which show
thier performance relative to the performance of others?
  Best
  Humphrey



---------------------------------
Do you Yahoo!?
 Next-gen email? Have it all with the  all-new Yahoo! Mail Beta.

[statisticsdoc]

Humphrey,

There are two ways to compute percentile scores in SPSS:

You can use menus to compute percentile ranks as follows:

1.)    Under the Transform menu, choose Rank Cases…
2.)    Choose the variable containing the raw test scores
3.)    Click on the Ties… box and choose High as the Rank Assigned to Ties
4.)    Click on the Rank Cases: Types… box and Check Fractional rank as %
5.)    Uncheck Rank (Unless you want cumulative frequencies)
6.)    Click on OK
7.)    SPSS will label the variable that contains the percentile ranks
"PCT001".
You can rename PCT001 with a clearer name if you wish.

You can also standardize the variable, and then use COMPUTE to transform the
z-score into the corresponding percentile score, but I would not recommend
that unless you are reasonably sure that your data are normally distributed.
This method is handy when you are dealing with a very large file of test
scores, as you are, that are normally distributed.  You can use the menus to
compute percentile scores via standard scores as follows:

1.)    Under the Analyze menu, choose Descriptive Statistics…, Descriptives
2.)    Choose the variable containing the raw test scores
3.)    Check the box Save Standardized values as variable.
4.)    Click on OK.
5.)    SPSS will label the variable that contains the standard scores "zx".
6.)    Under the Transform menu, choose Compute…
7.)    Fill in zx as the Target Variable and Percentile Rank as the label.
8.)    In the box Numeric Expression type in:  CDFNORM(zx)*100
9.)    Click on OK

Again, you can rename the variable with the percentile scores with a clearer
name.

You may wish to set your output file to record syntax that you can cut,
paste and re-use.

HTH,

Stephen Brand

For personalized and professional consultation in statistics and research
design, visit
www.statisticsdoc.com


-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]]On Behalf Of
Humphrey
Sent: Wednesday, July 12, 2006 5:12 AM
To: [hidden email]
Subject: percentile scores


Dear everyone,
  How can I get percentile scores for each case who has taken a reading test
in a population of 10000?
  I have got their total raw scores but I want percentiles which show thier
performance relative to the performance of others?
  Best
  Humphrey



---------------------------------
Do you Yahoo!?
 Next-gen email? Have it all with the  all-new Yahoo! Mail Beta.

[Frank Berry]

Hi,

Is there a white paper that explains a formula for each of the following percentiles in spss? When there is missing values in a numeric variable ranging from 0 to 100 (all integers), would the same formula for percentiles applies to missing values in that variable? For example, an equal percentile can be obtained for values of 49, 50 - missing and 51. Or in other cases, same value of 49 could have two or more percentiles.

TIA.
Frank

  /PERCENTILES= 1 2 3 4 5 6 7 8 9 10
 11 12 13 14 15 16 17 18 19 20
 21 22 23 24 25 26 27 28 29 30
 31 32 33 34 35 36 37 38 39 40
 41 42 43 44 45 46 47 48 49 50
 51 52 53 54 55 56 57 58 59 60
 61 62 63 64 65 66 67 68 69 70
 71 72 73 74 75 76 77 78 79 80
 81 82 83 84 85 86 87 88 89 90
 91 92 93 94 95 96 97 98 99


Statisticsdoc <[hidden email]> wrote: Humphrey,

There are two ways to compute percentile scores in SPSS:

You can use menus to compute percentile ranks as follows:

1.)    Under the Transform menu, choose Rank Cases…
2.)    Choose the variable containing the raw test scores
3.)    Click on the Ties… box and choose High as the Rank Assigned to Ties
4.)    Click on the Rank Cases: Types… box and Check Fractional rank as %
5.)    Uncheck Rank (Unless you want cumulative frequencies)
6.)    Click on OK
7.)    SPSS will label the variable that contains the percentile ranks
"PCT001".
You can rename PCT001 with a clearer name if you wish.

You can also standardize the variable, and then use COMPUTE to transform the
z-score into the corresponding percentile score, but I would not recommend
that unless you are reasonably sure that your data are normally distributed.
This method is handy when you are dealing with a very large file of test
scores, as you are, that are normally distributed.  You can use the menus to
compute percentile scores via standard scores as follows:

1.)    Under the Analyze menu, choose Descriptive Statistics…, Descriptives
2.)    Choose the variable containing the raw test scores
3.)    Check the box Save Standardized values as variable.
4.)    Click on OK.
5.)    SPSS will label the variable that contains the standard scores "zx".
6.)    Under the Transform menu, choose Compute…
7.)    Fill in zx as the Target Variable and Percentile Rank as the label.
8.)    In the box Numeric Expression type in:  CDFNORM(zx)*100
9.)    Click on OK

Again, you can rename the variable with the percentile scores with a clearer
name.

You may wish to set your output file to record syntax that you can cut,
paste and re-use.

HTH,

Stephen Brand

For personalized and professional consultation in statistics and research
design, visit
www.statisticsdoc.com


-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]]On Behalf Of
Humphrey
Sent: Wednesday, July 12, 2006 5:12 AM
To: [hidden email]
Subject: percentile scores


Dear everyone,
  How can I get percentile scores for each case who has taken a reading test
in a population of 10000?
  I have got their total raw scores but I want percentiles which show thier
performance relative to the performance of others?
  Best
  Humphrey



---------------------------------
Do you Yahoo!?
 Next-gen email? Have it all with the  all-new Yahoo! Mail Beta.



---------------------------------
How low will we go? Check out Yahoo! Messenger’s low  PC-to-Phone call rates.

[Dale Glaser]

Hi everybody......I'm working on a project whereby we have multiple raters ( 6 Physicians) rating multiple patients (17 of them), but a physician never rates the individual patient more than once.  So we have a rater x individual interaction, variation which can be decomposed via ANOVA to compute the dependability coefficients, at least for single DV's. However  there are four DV's that we desire to analyze simultaneously, and Shavelson and Webb (1991) briefly discuss this for only one paragraph in their text on the final page.  At first I was thinking of casting this as a MANOVA problem, but given these are just binary variables (yes/no) it would seem to run amiss of the ANOVA assumptions (though I notice in Nunnally and Bernstein they use binary variables for the ANOVA in a G-Theory context).  So what strategies have you employed in a multivariate context when you have multiple raters for multiple patients/objects and multiple DV's?..............any help would be
 incredibly appreciated!!.........thank you...Dale

Dale Glaser, Ph.D.
Principal--Glaser Consulting
Lecturer--SDSU/USD/CSUSM/AIU
4003 Goldfinch St, Suite G
San Diego, CA 92103
phone: [phone]
fax: [phone]
email: [hidden email]
website: www.glaserconsult.com

[alexwin]

Small corrections: to obtain percentile scores using formulas described in psychometric literatuire (see, for instance, Crocker, L., & Algina, J. (1991). Introduction to classical and modern test theory. Orlando, FL: Harcourt Brace Jovanovich.), I would use slightly different options:

1)    Under the Transform menu, choose Rank Cases&#8230;
2)    Choose the variable containing the raw test scores
3)    Click on the Ties&#8230; box and choose MEAN as the Rank Assigned to Ties
4)    Click on the Rank Cases: Types&#8230; box and Check Fractional rank as %
5)    Check Rankit under Proportion Estimation Formula
6)    Uncheck Rank (Unless you want cumulative frequencies)
7)    Click on OK


Dr. Alexander Vinogradov, Associate Professor
Sociology and Psychology Faculty
National Taras Shevchenko University
Ukraine

>> Statisticsdoc <[hidden email]> wrote: Humphrey,

>> There are two ways to compute percentile scores in SPSS:

>> You can use menus to compute percentile ranks as follows:

>> 1.)    Under the Transform menu, choose Rank Cases&#8230;
>> 2.)    Choose the variable containing the raw test scores
>> 3.)    Click on the Ties&#8230; box and choose High as the Rank Assigned to Ties
>> 4.)    Click on the Rank Cases: Types&#8230; box and Check Fractional rank as %
>> 5.)    Uncheck Rank (Unless you want cumulative frequencies)
>> 6.)    Click on OK
>> 7.)    SPSS will label the variable that contains the percentile ranks "PCT001".