====== Directory Structure for Input Data ======

There is a basic directory structure for Sift's input data that aligns with some useful concepts from the experiments that produced the data. This directory structure organizes the [[Visual3D:Documentation:Definitions:File_Formats:CMZ_Format_|CMZ files]] and [[Visual3D:Documentation:C3D_Signal_Types:C3D_Format|C3D files]] that contain the information relevant for analysis. This structure has 5 levels, from root folder to deepest leaf they are:

  - Study
  - Group
  - Session
  - Task
  - Trial

==== Study ====

Although the name of this directory level suggests that the data it contains is only used for one study, this is not necessary. As a top-level concept this is the largest, most general database that is stored in on location. This could be specific to a study, or it could be specific to a project, researcher, lab, or consortium. In these latter cases it is possible to define [[Sift:Application:Query_Builder_Dialog|queries]] to extract the specific signals that are desired for an individual study.

==== Group ====

This level of the directory structure is optional, but it allows the researcher to divide c3d files according to desired parameters, e.g., Women - Men, Old - Young. If this level is omitted from the structure then individual C3D files can be [[Visual3D:Documentation:Definitions:Tag|tagged]] with the necessary parameters to allow for their specific selection.

==== Session ====

This directory level can be conceived as a single day (or a single effort) of data collection within the database. This is the most important level as this is where the [[Visual3D:Documentation:Definitions:File_Formats:CMZ_Format_|CMZ file]] and log files get stored. This is also the level of the directory where static models are stored for all subjects involved in the session.

==== Task ====

This level of the directory allows the researcher to divide c3d files according to the desired activity, e.g., walking, running, jumping, etc. As with group-level parameters, C3D files can be coded with these different tasks by using [[Visual3D:Documentation:Definitions:Tag|tags]].

==== Trial ====

At this level of the directory structure we have individual trials. This means that we have the individual C3D files that are recorded by the motion capture system.