A good data definition provides ALL the characteristics of forms (questionnaires, CRFs) and the associated variables. What is needed is good old "TLV".
| Stands For.. | Overview | |
|---|---|---|
T | Type of Variable | The most common types are dates, number, coded variables (e.g., 0 = No, 1 = Yes;). |
L | Layout and Logic | Indicate the look and feel of the variable, and when it should be displayed (e.g., only show if subject is a male). |
V | Validation | Indicate the rules that govern the acceptable variable values (acceptable range, units) |
What To Do
Use A Spreadsheet
Document your data definition using the spreadsheet here.
Leverage Standards
Learn About Data Definition Standards (see here)
Mark It UP
When sending us a form, mark it up with the data definition.
Example Marked Up Form
Keep It Simple
Forms should use the cleanest, simplest layout possible. Standard practice is to use one-row-per-variable (examples here).
Leverage Visual Validation
A form's spatial and visual layout can be it's most important validation (see examples here).
Indicate Timing
Document which forms are collected with each study event by completing the Data Collection Schedule (see Data Collection Schedule.doc).