1. How does QPL handle missing data?
2. Why doesn't the fixed-format export file contain the "built-in" fields, such as the user name, as the tab-delimited and askSam file formats?
3. Why are the labels in the SAS and SPSS-generated programs so short?
4. OPENEND questions are defined as numbers in the SAS and SPSS files. What happened to the text responses?
5. Where is the private.key file?
6. The data files I export from the web survey web site are binary files, not ASCII, and can't be loaded into any of my analysis software packages. What's the problem?
7. How can I load the on-line Statistics Summary report into Excel?
8. The fixed format data file I export from the site doesn't match the column specifications listed in my SAS or SPSS file. Why not?
9. When I export the content analysis data file, I find that that some tags are not applied to the same comments that I set when assigning topic tags. What's wrong?

1. How does QPL handle missing data?

Missing data is allowed and handled differently according to the question type. STRING. OPENEND, NUMBER and DATE questions may be left blank and are coded as NULL values in the data base and as blank values in the export files. A MULT question will always be coded as a number which will be the default answer you specified or zero if you specified that no answer should initially be checked. A CHECK question will always be one or zero, indicating checked or not checked.

2. Why doesn't the fixed-format export file contain the "built-in" fields, such as the user name, as the tab-delimited and askSam file formats?

This was added as an option starting with Version 5.04.002.

3. Why are the labels in the SAS and SPSS-generated programs so short?

Previous versions of SAS and SPSS had more limited label lengths. The labels in the programs generated by QPL have been increased as of version 5.03.009. Variable labels may now be up to 255 characters long (with all HTML codes removed), and value lables for multiple choice questions may be up to 60 characters long for SPSS and 40 characters long SAS.

4. OPENEND questions are defined as numbers in the SAS and SPSS files. What happened to the text responses?

The fixed format export data file does not include the text from OPENEND questions since fit in a it will not fit in a fixed field and since SPSS and SAS do not handle open-ended text well. Instead, the number of characters the respondent typed is put into the OPENEND field in the fixed format data file and the SAS and SPSS programs define this field as a number. (Blank spaces before and after the text is removed before the number of characters is computed.) This lets you do some minimal analysis on how much text was entered, if any. The tab delimited and askSam export files contain the full text of OPENEND responses.

5. Where is the private.key file?

The private.key file is created by the web server administrator when he performs the one-time server set up tasks. (See also the QPL help page, "Server Set Up," and the readme.txt file packed with the qpl5_server_setup_2003-09-12.tgz server setup files for more information.) A copy of the file should be located in the temporary directory on the server he used to unpack the set up files and run the setup.sh script.

You must copy this file to the project directory on your computer, with the .key and .blg files you export from the web site before decrypting. (See the QPL help page, "Exporting Data Files for Analysis," for more information.)

Starting with Version 5.04.002, however, the private.key file is not used because export data files are not encrypted.

6. The data files I export from the web survey web site are binary files, not ASCII, and can't be loaded into any of my analysis software packages. What's the problem?

The export files are encrypted. This is done to prevent anyone from accessing your data while it is sitting exposed on your server or being transported to you. (After you log off the site, the encrypted and unencrypted data files are scratched.) You must decrypt each data file after you export it before it may be used for analysis. (See the QPL help page, "Exporting Data Files for Analysis," for more information.) You also must take care to always export both the .key and .blg files together. The .key file changes each time a file is exported, and can only be used to decrypt the .blg file that was generated with it.

Starting with Version 5.04.002, however, export data files are not encrypted.

7. How can I load the on-line Statistics Summary report into Excel?

Copy and paste the tables you want from the web page to Excel. You can use the Paste Special... option, 'Text.' in Excel if you don't want them to come in with any HTML formatting (i.e., row colors and font settings).

8. The fixed format data file I export from the site doesn't match the column specifications listed in my SAS or SPSS file. Why not?

A low-level PHP function that QPL uses to format floating point numbers was changed as of PHP Version 4.3.7 to be consistent with how these formats work with other languages like C. (See PHP Bug #29286 printf/sprintf floating point output change.) QPL 5.04.012 was updated to accommodate this change in PHP.

The impact on the QPL export function was to shrink the size of the space allocated to a floating point number in the fixed format file, thus throwing off the locations of all the other fields on that data card, thus making it appear that incorrect data was put in the file. Numbers defined without any decimal places, however, are formatted correctly.

This change affects QPL NUMBER questions that were defined to include one or more decimal places:

.QUESTION = N1, TYPE = NUMBER = "##.#"
...

Thus, projects built with QPL 5.04.010 and earlier, and running under a PHP 4.3.6 and earlier, will create correct fixed format files, while projects running under PHP 4.3.7 and later will create incorrect fixed format files.

Projects built with version of QPL 5.04.012 or later require PHP 4.3.7 or later to create correct fixed format files.

Note: The format specification for fixed format files are stored in the struct table's q_format column. Previously, the format for this example would have been set to "%f2.1"". Now it should be set to "%4.1" (i.e., total field width of 3 plus 1 for the decimal point). The total field width generated by this format will always be three characters (the decimal place is implied in the SAS and SPSS system files - - the decimal point character generated by the format is removed by the QPL export function before it is written to the data file).

The format for live projects can be corrected, if necessary, by updating the struct table, such as…

USE myproject;
UPDATE struct SET q_format='%4.1f' WHERE q_varname='N1';

9. When I export the content analysis data file, I find that that some tags are not applied to the same comments that I set when assigning topic tags. What's wrong?

The tag names were not being put at the top of the columns which hold their data. (The tag names were put into sorted order alphabetically while the data columns were simply built in the order that the tags were created on the web site.) This has been corrected as of QPL Version 5.04.012.

QPL Home Send comments to Kevin Dooley.

Site Map