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Do-it-yourself control and data file construction |
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There is a control and data file setup procedure. It is even easier!
Here is a step-by-step guide to setting up and running Winsteps. It is a little tricky the first time, but you'll soon find it's a breeze!
The first stage is to set up your data in a rectangular data file in "MS-DOS text with line breaks" format.
1. Obtain your data
You'll need to be a little organized. Think of your data as a wall of pigeon-holes.
(a) Each column corresponds to one item, probe, prompt, task, agent, ....
For each column, you will need an item name or label. Make these short, only one or two words long. Make a list of these in a document file. Put the label of the first item on the first line, etc. Put END LABELS on the line after the last item. Your list will look like this:
Eating Dressing .... Walking Stair climbing END LABELS
You can use Notepad or your own text editor or pull-down the Winsteps "Edit" menu, and select "Create/Edit file with Notepad"
(b) Each row of pigeon-holes corresponds to one person, subject, case, object, ...
You will need some useful identifying codes for each row such as age, gender, demographics, diagnosis, time-point. Winsteps doesn't require these. but its is much more useful when they appear. Give each of these identifiers one or two letter codes, e.g., F=Female, M=Male, and give each identifier a column of pigeon-holes.
(c) The Data must be carefully lined up. It is simpler if each data point, observation, response, rating can be squeezed into one character - numeric or alphabetic.
Now create the data file. It will look like something this:
M 29 B 001 210212110200102 F 27 W 002 122121010201020 F 32 H 003 222210102112100 M 31 W 004 002010021000210
or, less conveniently,
M29B001210212110200102 F27W002122121010201020 F32H003222210102112100 M31W004002010021000210
After the END LABELS line, or in a separate file, on each line enter the person identifying codes. Line them up so that each column has a meaning. This is easier if you set the font to Courier.
Then enter the responses, starting with the first item and continuing to the last. Do not place spaces or tabs between the responses. If the lines start to wrap-around, reduce the font size, or increase the page size.
Excel, SPSS, SAS, ACCESS Your data may already be entered in a spread-sheet, statistics program or database. "Copy and Paste", Save As, Export or Print to disk the data from that program into "DOS-text with line breaks" or ASCII file.
If the program puts in extra blanks or separators (e.g., Tabs or commas), remove them with a "global replace" in your text editor or word processor.
To replace a Tab with nothing, highlight the space where a Tab is. Then Ctrl+c to copy. Global replace. Ctrl+V put a Tab into "From". Put nothing in "To". Action Global Replace.
In Excel, reduce the column width to one column, then "Save As" Formatted Text (Spaced delimited) (*.prn)
In SPSS, see SPSS pull-down menu.
2. Set up your Winsteps Control and Data file
(a) Edit Template.txt Pull-down the Winsteps "Edit" menu, select "Create new control file from= ....\Template.txt"
The Template.txt will be displayed on your screen by Notepad or your own text editor.
(b) Template.txt is a Winsteps Control and Data file Find the three sections:
top: down to &END are Control Specifications we will edit this in a moment
middle: between &END and END LABELS are the Item Labels copy and paste the item labels from your list into this area. one item label per line, in the order of the labels.
bottom: below END LABELS are the data copy and paste the person labels and responses into this area. one person per line (row).
(c) Edit the Control Specifications
Find the line "Title=" Replace Put your page heading here with your own page heading.
Look at a data line, and count across:
If your codes are not numeric, then you will need to rescore them. See Data recoding
This is usually enough for your first Winsteps run.
(d) "Save As" the Template.txt file with your own file name. Winsteps accepts any valid file name.
3. Run Winsteps
To the prompt: Control file name? (e.g., KCT.txt). Press Enter for Dialog Box: Press the Enter key Select your control file from the dialog box Press the Enter key
Report output file name (or press Enter for temporary file): Press the Enter key
Extra specifications (if any). Press Enter to analyze): Press the Enter key This is used for making just-in-time changes to your control file instructions, for this run only.
4. Your analysis commences
5. Your analysis concludes.
If there is an error message: select "Edit Control File=" from the Winsteps Edit menu correct the control file save it select "Exit, then Restart Winsteps" from the Winsteps File menu
If "Measures constructed" - use the Output Tables pull-down menus to look at the Output Tables here is the list of output tables.
6. Exit Winsteps using the X in the top right corner. | ||||||||||||||||||||
Help for WINSTEPS® Rasch Measurement Software: www.winsteps.com.