Wu et al. (2020) use Google Maps to display Wright maps and other Rasch output. Here is how to do that. We will use GPSVisualizer at www.gpsvisualizer.com. Google Maps has many more capabilities if you want to go further.
In Winsteps, for statistics in the item file:
HLINES=Yes
ROW1HEADING= No
Output files menu: IFILE=
File format dialog box: tab-delimited
check "Labels in quotation marks"
Permanent file
Give the file a name, e.g., mymap.txt
GPSVisualizer expects the input file to have these column headings:
longitude: x-axis in range -180 to + 180 (choose the column for this)
latitude: y-axis in range -90 to +90 (choose the column for this)
longitude 0, latitude 0 is a point off the coast of Africa, so there is almost nothing in the background of the map.
name: the point label
most other column headings are ignored, but GPSVisualizer has many options, see its Tutorials
In GPSVisualizer,
Click "Choose file": mymap.txt - if you change mymap.txt you must "Choose File" again to upload the changes
Click "Map it" - the map should display in Google Maps.
For more control over the map, click "JPEG/PNG/SVG maps"
Background map: None
Title: (your choice)
Advanced options: Border = Yes
File #1: mymap.txt
and many more options. See its "Help", "Tutorials" and try outputting in other formats.
Wu H.-M., Shao Y., Chien T.-W. (2020) Student's Performance Shown on Google Maps Using Online Rasch Analysis. Journal of Applied Measurement, 21, 2, 225-234.
Example: using Example0.txt.
Output IFILE= with all columns tab-separated:
Change "MEASURE" to "Longitude"
Change "OUT.MSQ" to "Latitude"
Follow the instructions above.
When the map displayed, I chose "us: County Outlines" so that topographical features (such as islands near Africa) are not shown.
