PWT Reliability
How reliability for Point Walk Talk (2019) was accomplished
Last updated
How reliability for Point Walk Talk (2019) was accomplished
Last updated
A point is counted when the infant extended the arm (either fully or slightly bent) and index finger, palm down, in the direction of the stimulus.
Watch this example video:
Open the Point Reliability spreadsheet:
Fas-Phyc-PEB-Lab/Seedlings/Subject_Info_and_Paperwork/Point_Walk_Talk/Point_and_Walk_Reliability/Point/Point_Reliability.xlsx
For four randomly generated subjects, you will need to try to find the first observable instance of pointing between the lab data (eye tracking videos, recorded at 6, 8, 10, 12, 14, 16, and 18 months) and home data (monthly home visit videos).
Eye tracking videos can be found in Subject_Files/In-Lab_Visit/Eyetracking folders. To find the first point, you'll be working up through the months from 6 months until you find a video where you see a point. Sometimes there will be a few eye tracking videos in a particular month. You should check all of the available videos for a month before moving on to the next month.
To start, open a new Datavyu spreadsheet. Click Add Data and navigate to the first 6 month eye tracking video. Use the shuttle function to play the video at 2x speed until you see the child point. You can press shuttle again to scan faster--find a speed that you feel comfortable that you'll be able to catch the infant pointing. If you don't see any pointing in the 6 month video, you can close the video using the small "x" on the Data Viewer Controller.
Click Add Data again and navigate to the 8 month eye tracking video. Use the same process--shuttle through the video until you see the child point. If you don't see a point, you can close that video and move on to the next video.
Continue until you find a video where the child points.
Once you've identified where the pointing behavior begins for that child, you'll need to find the earliest observation of a point in the home videos.
You can begin with the month where you identified a lab visit point. If you do see the child point in the home video, check one home visit earlier. Keep checking earlier until you don't find a point. Note the earliest home visit point on the spreadsheet. If you do NOT see a point in the equivalent month to the lab video, you should still check the earlier videos and then check the later home visits. Basically, you can use the lab video as a starting point, and then expand out both earlier and later from there to identify the earliest HOME point.
Once you've found the first identifiable lab and home points, note the month and timestamp of the points in the Point Reliability spreadsheet. Fill out both Lab Video and Home Video columns. In the Lab Video Name column, record the name of the mp4 you found it in (i.e. 09_06_etracking2).
Our criteria for walking is 10 continuous steps unassisted. Infant should be alternating left and right feet and should not fall or require support.
Watch this example video:
Open the Walk Reliability spreadsheet:
Fas-Phyc-PEB-Lab/Seedlings/Subject_Info_and_Paperwork/Point_Walk_Talk/Point_and_Walk_Reliability/Walk/Walk_Reliability.xlsx
Your job is to find the earliest instance we have on video of the target child walking 10 continuous steps with no support.
For the 4 randomly selected participants in the Walk Reliability spreadsheet, you can work backwards looking at their home recordings to see when they started walking.
Start at the month 16 home visit. If the child is clearly walking and it looks like they've been walking for a while, you can skip to month 14. If they are also walking in month 14, you can skip to month 12. By then, you might find that walking has disappeared and the baby is only crawling/standing/cruising. You should then move back up one month and check the 13 month home visit for walking. If you do not find 10 continuous steps in the 13 month video, open back up the 14 month video and find the first instance of 10 continuous steps. Make note of the month and timestamp in the Walk Reliability spreadsheet. If they are not walking in the month 16 video (or you don't see 10 steps), you should move up to the 17 month video.
Navigate through the videos in the same way as is described above for pointing with a blank Datavyu spreadsheet and adding and removing videos using Add Data and the little x on the controller. Use the shuttle button to skip quickly through sections of the video where the child is sitting but slow it back down to be able to count steps where appropriate.
