Internet Measurement Data Catalog

A few of the most useful paths through the catalog.
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This page will walk you through a few of the most useful paths you can use to find Data in the catalog.

The basic procedure for obtaining data is:

1. find the Collection you want (optional, but recommended)
2. find the Data you want
3. find the Packages that contain that Data
4. find Locations for those Packages.

A simplified road map like the following will appear near the top of pages that are directly on the path to acquiring data. Your current progress along the path is indicated by the highlighted item, and (in graphical browsers) a series of paw prints leading up to it.

Where to start

Unless you know exactly what you're looking for, the best way to start looking is usually via Data Collections. You can either Browse or Search:

• 
  To browse, follow the Browse link at the top of any IMDC page. Under Featured Data Collections or Recently Contributed Collections, click on any collection name to go to a Collection Detail page that describes that collection in detail. Or, under Browse Collections by Keyword, click on any keyword to see Collection Search Results listing a set of Collections that match that keyword.
• 
  To search, follow the Search link at the top of any IMDC page. Enter a word or phrase in the Simple Search box and select Data Collections from the object type menu. IMDC will search for the text within the name, short description, and keywords of all Collections in the catalog. A * character in the search string acts as a wildcard that will match any number of characters; a ? will match any one character. Clicking Go will take you to a Collection Search Results page listing the Collections that match your query.
• 
  You can also search for Data directly, but unless your query is very specific, doing so will likely produce too many results to be very useful.

Collection Search Results

Searching for Collections leads to a Collection Search Results page containing a table summarizing the Collections matching your search criteria. Clicking a right-triangle (or +, in non-graphical browsers) next to any object listing will expand the entry to show more information about the object; clicking a down-triangle (or -) will collapse the entry to a single line. You can also click on the name of any Collection to view a Collection Detail page. This is true in general throughout IMDC: the name of each object is a hyperlink to a Detail page describing the object in full detail. On the Collection Search Results page, clicking on the file count will take you to a Data Search Results page listing the Data objects belonging to the collection.

Collection Details

A Collection's Detail page describes the Collection in full detail. From here, clicking on the contents count will take you to a Data Search Results page listing the Data objects belonging to the collection.

Data Search Results

On the Data Search Results page, again, rows in the table can be expanded or collapsed, and Data names are links to Data Detail pages. When you have identified the data objects you want, select each one by checking its checkbox, and use the Find packages button to search for Packages that contain those data objects. For convenience, there is a set of buttons below the table for selecting or unselecting multiple items at once. If the search results do not fit on a single page, you can browse to other pages within the search results, and IMDC will remember any checkmarks you have made on any page.

Data Details

Alternatively, if you want only one data item from the Data Search Results, you can click on its name to see its Detail page, and use the Find packages button there.

Packages

The next page will contain a summary of Packages containing the data you selected. A Package is a real downloadable file that contains one or more Data items. Each package includes a list of selected contents; each may contain multiple Data objects, and the same Data object may appear in multiple packages. As always, the name of each object is a link to a Detail page. Check off the packages you want, and use the Find locations button to find their locations.

Locations

The last page in the sequence summarizes the Locations of each package you have selected. Some Locations may have a URL linked directly to a copy of the package file, although it may be password-protected or otherwise restricted. If there is no URL, or the URL is restricted, there will be further instructions on how to proceed.

This page described only a few possible paths through the system, which are probably the most useful in most situations. But there are many other ways to find Data and metadata. There are simple and advanced searches for all types of objects, and objects are heavily cross-linked to related objects, including links embedded within objects' descriptions. Explore, and use whatever works best for you.