DATA TITLE: Longitudinal Shoe Study: Digital Photos of Shoe Soles
PROJECT TITLE: CSAFE Longitudinal Shoe Study

== AUTHORS ==
Author: Susan Vanderplas
ORCID: 0000-0002-3803-0972
  Institution: University of Nebraska Lincoln
  Email: svanderplas2@unl.edu

Author: Alicia Carriquiry
Institution: Center for Statistics and Applications in Forensic Evidence and Statistics Department, Iowa State University

Author: James Kruse
Institution: Department of Sociology, Iowa State University

Author: Guillermo Basulto-Elias
Institution: Institute for Transportation, Iowa State University

Author: Stacy Renfro
Institution: Center for Statistics and Applications in Forensic Evidence, Iowa State University


== ASSOCIATED PUBLICATIONS and RESOURCES: ==
Center for Statistics and Applications in Forensic Evidence Website: https://forensicstats.org/
Github repository for documentation: https://github.com/CSAFE-ISU/Longitudinal_Shoe_Study


== Overview ==
Digital photographs of shoe soles obtained following the CSAFE Digital Camera data collection procedure.

== FILE DIRECTORY ==
----- FILE LIST-----
- Method_Image_Replicate_Codebook.csv: Contains descriptions of the metadata encoded in each file name.
- Variable_Codebook.csv: Contains descriptions of the auxiliary data collected along with the images (survey results, participant height and weight, number of steps, etc.)

- CameraImages.zip
Contains the scans of the shoe prints taken with the 2D Digital scan methodology. Images are named with respect to the following convention:
  `{ID#}_{Date}_{Method}_{Image#}_{Rep#}_{ID of technician(s)}` where:
  - ID# is a 6 digit number followed by {RL} indicating right (R), or left (L) shoe. The first three digits are the shoe ID and the second three digits are a checksum.
  - Date, in yyyymmdd format, indicating the date the data was collected (not the date the shoes were turned in for data collection).
  - Method_Image_Replicate: these fields are hierarchically determined - the meaning of the values for image and replicate depend on the method.
    - Method: Digital Camera = 4
    - Image: two images per shoe
    - Replicate: one replicate per shoe/image
  - ID of technician(s): Some methods require that one individual wear the shoe, another individual assists with the data collection, and (in some cases) a third individual digitizes the information. In those cases names are separated by underscores.
Also contains 3 separate comma separated data files:
  - Shoe-info.csv, which contains information relating to the specific shoe (size, model, color, wearer characteristics)
  - Visit-info.csv, which contains information relating to the specific data collection visit (e.g. survey answers, pedometer readings)
  - Image-info.csv, which contains information relating to the specific image (collection method, replicate number, workers involved in the collection)


== DATA COLLECTION METHODS ==
The study consists of 160 pairs of shoes:
  - Two models (Nike Winflo 4 or Adidas Seeley)
  - Four possible sizes for each model
Each pair of shoes was worn for at least 10,000 steps per week over a 6-month period, with multiple measurements of the shoe soles taken initially and during three check-in periods spaced at approximately 5 week intervals.

Prints and measurements for this data set were taken using the following equipment: DSLR camera. This method is documented in the CSAFE Longitudinal Shoe Study Collection Procedures Collection (DOI: http://doi.org/10.25380/iastate.8016341), specifically the following documents:
  - Digital_Camera.pdf


== LICENSING ==
This work is licensed under a Creative Commons Attribution 4.0 International License. (https://creativecommons.org/licenses/by/4.0/)