This codebook.txt file was generated on 2019/08/26 by Hannah Walter ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset APAL "Sensitivity to changes in dynamic affordances for walking on land and at sea" Data Sets 2. Author Information: Principal Investigator Contact Information Name: Hannah Walter Institution: University of Minnesota Affordance Perception-Action Laboratory (APAL) Email: walte666@umn.edu Associate or Co-investigator Contact Information Name: Ruixuan Li Institution: University of Minnesota Email: lixx3747@umn.edu Associate or Co-investigator Contact Information Name: Nicolette Peterson Institution: University of Minnesota Email: pete9746@umn.edu Associate or Co-investigator Contact Information Name: Thomas Stoffregen Institution: University of Minnesota Email: tas@umn.edu Associate or Co-investigator Contact Information Name: Jeffrey Wagman Institution: Illinois State University Email: jbwagma@ilstu.edu 3. Date of data collection (single date, range, approximate date) 2018 4. Geographic location of data collection (where was data collected?): Experiment 1: University of Minnesota, Williams Arena Experiment 2: Data was collected aboard RV Sally Ride on transit from San Diego to Portland 5. Information about funding sources that supported the collection of the data: Publication of this project was supported by an Illinois State University Outstanding Researcher Award to Jeffrey B. Wagman. -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: CC0 1.0 Universal 2. Links to publications that cite or use the data: None 3. Links to other publicly accessible locations of the data: None 4. Links/relationships to ancillary data sets: None 5. Was data derived from another source? No 6. Recommended citation for the data: Manuscript: Walter, H., Peterson, N., Li, R., Wagman, J. B., Stoffregen, T. A. (2019) Sensitivity to changes in dynamic affordances for walking on land, and at sea. PLoS One. Dataset: Walter, H., Li, R., Peterson, N., Stoffregen, T., & Wagman, J. APAL "Sensitivity to changes in dynamic affordances for walking on land and at sea" Data Sets. Data Repository for the University of Minnesota (DRUM). https://doi.org/10.13020/HFB0-DD13 --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: Experiment1_Terrestrial_DATA.xlsx Short description: An excel file containing the performance, judgment, and speed data collected at the Williams Arena in experiment one. B. Filename: Experiment2_Nautical_DATA.xlsx Short description: An excel file containing the performance, judgment, and speed data collected aboard the RV Sally Ride in experiment two. 2. Relationship between files: All files contain collected data or are forms used in the 2019 Walking experiments, published together in one study. 4. Are there multiple versions of the dataset? No. -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: Experiment 1 (Terrestrial): Demographics Our sample comprised 14 individuals (5 men and 9 women), ranging in age from 18 to 76 years (mean = 39.21 years), in height from 1.44 to 1.81 m (mean = 1.65 m) and in weight from 49.90 kg to 103.41 kg (mean = 70.18 kg) Setting and apparatus The study was conducted on an indoor basketball court. In some conditions, athletic weights were applied to the body. We used a weighted vest (j/fit, Vancouver WA), in which 9.1 kg were distributed symmetrically left to right, and front to back. We also used two soft, wrap-around athletic weights (Synergee, Thunder Bay Ont) each 4.55 kg, that could be secured at the ankle using Velcro. Procedure We created a pathway using matte tape on the court, parallel to the sidelines. Following previous studies [5-6], the pathway was 8.9 m long × 0.3 m wide. We used a within-participants design. Participants were tested with their shoes on (at sea, in Experiment 2, this was required). In the No-Weight condition, the participant wore No-Weights attached to the body. In the Torso-Weight condition, the participant wore the weighted vest. In the Ankle-Weight condition, the participant wore one 4.55 kg weight attached at each ankle. Judgment task The participant was asked to look at the designated path and estimate "if you were walking comfortably, how far do you think you could walk along this path without stepping on or over the lines?" To report estimated distance, the participant instructed an experimenter where to place a marker (a 0.25 m length of a wooden 4 x 4) along the path. At the beginning of the trial, the experimenter stood near the participant, facing them, and slowly walked backward along the path until instructed to stop by the participant (S1 Video B). Each participant gave eight judgments for each condition (No-Weight, Torso-Weight, Ankle-Weight), for a total of 24 judgments. Across participants, we counterbalanced the order in which the three conditions were presented. We repeated the six possible condition orders in a fixed sequence across successive participants. Performance (walking) task After completing the judgment task, participants were asked to walk comfortably along the path: "Please do not look at your feet. Keep your eyes on the end of the path and walk so as to avoid stepping on the lines." For each condition, the participant completed a total of 12 trials, comprising six laps (out and back). Stepping on or over the lines with any part of either foot was classified as a "fault" and the walked distance was recorded from the spot of the fault. For each trial, the participant indicated that they were ready, after which the Experimenter gave a "go" signal and started a handheld stopwatch (S1 Video C). Each of three experimenters watched for faults, with one experimenter on each side, walking behind so as to be able to monitor footfalls while remaining outside the participants field of view, while one experimenter remained at the starting point. The stopwatch was stopped when the participant crossed the end line or when a fault was verbally indicated, and the duration of the trial was recorded. Experiment 2 (Nautical): Demographics Our sample comprised 9 individuals (8 men and 1 women), ranging in age from 22 to 62 years (mean = 39.78 years), in height from 1.6 to 2.03 m (mean = 1.75 m) and in weight from 49.9 to 108.8 kg (mean = 81.13 kg), and with 1-37 years (mean = 15.1 years) experience working at sea. Participants were working crew members who volunteered (with the CaptainŐs permission), taking time off from their regular duties. None of these individuals had participated in our earlier studies (Walter et al., 2017; 2019). Proceedure Except as indicated below, in all other respects, the procedure in Experiment 2 was identical to that of Experiment 1. One pathway (8.9 m long x 0.2 m wide) was created using clearly visible gaffer tape. On the first day at sea, a preliminary assessment suggested that walking was not strongly constrained when the path width was 30 cm. For this reason, in Experiment 2, path width was set at 20 cm. The pathway was parallel to the ship's short (athwart) axis. Judgment data were collected with the participant standing at one end of the pathway. At this starting location, participants stood with their feet on the taped lines. The purpose was to standardize foot position to reduce variation in the walking distance. We used a within-participants design, in which each individual participated in both conditions. 3. Instrument- or software-specific information needed to interpret the data: All data were collected through the use of tape measurers and timers, which requires no software to interpret. 4. Standards and calibration information, if appropriate: None 5. Environmental/experimental conditions: Experiment 1: The study was conducted on an indoor basketball court. The court was not in use and was free from clutter. Experiment 2: The study was conducted during a 5-day cruise aboard the R/V Sally Ride, from San Diego CA to Newport OR. The ship was 86.26 m long with a 15.24 m beam. It displaced 3043 tons, and cruised at 10-12 knots. Testing was conducted on the rear deck of the ship (the fantail), which was free from clutter. 6. Describe any quality-assurance procedures performed on the data: Data were reviewed every day upon completion of collection. Analyses and final datasets were also reviewed by each researcher to ensure errors were prevented. 7. People involved with sample collection, processing, analysis and/or submission: Hannah Walter, Ruixuan Li, Nicolette Peterson, Thomas Stoffregen, Jeffrey Wagman ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: [Experiment1_Terrestrial_DATA.xlsx] ----------------------------------------- 1. Number of variables: 3 variables (torso, ankle, and none) These three variables are repeated in 8 judgment and 12 performance trials, as well as the times for the performance trials (12x). Each "task" (judgment, performance, time) has its own sheet. 2. Number of cases/rows: These variables are repeated 8 times for judgments, 12 times for performance, and 12 times for the times of each performance trial. There are 14 rows (participants). 3. Missing data codes: None 4. Variable List A. Name: Torso Description: These trials utilized the torso weight. B. Name: Ankle Description: These trials utilized the ankle weight. A. Name: None Description: These trials utilized no additional weight. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: [Experiment2_Nautical_DATA.xlsx] ----------------------------------------- 1. Number of variables: 2 variables (ankle and none) These two variables are repeated in 8 judgment and 12 performance trials, as well as the times for the performance trials (12x). Each "task" (judgment, performance, time) has its own sheet. 2. Number of cases/rows: These variables are repeated 8 times for judgments, 12 times for performance, and 12 times for the times of each performance trial. There are 9 rows (participants). 3. Missing data codes: None 4. Variable List A. Name: Ankle Description: These trials utilized the ankle weight. B. Name: None Description: These trials utilized no additional weight.