With any luck, they will come from someone else, but eventually we all end up helping others deal with putting data files together. Methods for recording data often appear to be selected as afterthoughts, and they often use tools designed for other purposes. Things haven't changed much over the last six year. Data continue to arrive from a variety of sources, entered in ways suggesting they weren't necessarily recorded with an eye toward future analysis. Every major statistical package has its own data sheet for recording data.
Some programs contain full data entry packages.
Once they are in machine readable form, any experienced programmer should be able to rearrange them for you if they are not in the format you need. For example, in a study of two treatments, a researcher might put the identification numbers and responses of those on one treatment in the first two columns of a spreadsheet and the identification numbers and responses for the other treatment in the next two columns. This left me having to cut out the third and forth columns, paste them below the first two columns, and add an additional column containing a subject's treatment. This note will provide some guidelines to minimize the work of importing data into standard statistical packages. The standard model for data is a matrix or table of numbers where each row corresponds to an individual subject and each column corresponds to a different variable or measurement.