Cannabis Timeline Followback

Technical Manual

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond

Created: January 20, 2013

Last Modified: January 12, 2025 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a Cannabis timeline Follow-Back calendar. The implemented template procedure tracks the use of cannabis over the last 30 days. Note: the calendar has to be filled out all at once.

References

For more information about timeline Follow-Backs at: https://www.nova.edu/gsc/online_files.html#time_followback

Duration

5 minutes

Description

Participants are asked to fill out a calendar with their cannabis use for the last 30 days, starting with yesterday.

For each day participants are asked to fill in: - quantity - method - or 'No use'

Procedure

1. Screen that asks for information input about start day ("yesterday") -> year, leap year, month, day, weekday
2. Screen that displays instructions (edit instructions under EDITABLE CODE -> Editable Instructions)
3. Calendar Display: a calendar display with the last 30 days filled in with the appropriate days
(all 30 days are displayed on one page)
=> each days asks for a) quantity b) method or c) No use checkbox
=> a screenshot is taken of the filled in calendar (default; works on Inquisit Lab only)
=> computer totals the quantities and calculates mean quantity for the last 30 days
=> computer totals the number of times participants select "no use"

Instructions

Instructions can be edited in section Editable Instructions. The default instructions reference
cannabis use.

Summary Data

File Name: timelinefollowback_summary.iqdat

Data Fields

NameDescription
inquisit.version Inquisit version number
computer.platform Device platform: win | mac |ios | android
computer.touch 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities
computer.hasKeyboard 0 = no external keyboard detected; 1 = external keyboard detected
startDate Date the session was run
startTime Time the session was run
subjectId Participant ID
groupId Group number
sessionId Session number
elapsedTime Session duration in ms
completed 0 = Test was not completed
1 = Test was completed
yesterdayDate Stores yesterday's date as a string (e.g. 5/20/2013)
yesterdayWeekday Stores yesterday's weekday as an integer (e.g. 1 for Monday, ..., 7 for Sunday)
leapYear Stores whether the year is a leap year
totalAmount Sums up all the quantities that participants reported over the 30 day span; regardless of method
meanAmount Mean daily quantity consumed (over 30 days); regardless of method
countNouse Sums up how often a participant has checked the nouse checkbox
Individual Performance Metrics Points
date11 - date61 Individual dates of each of the calendar boxes (e.g. 11 = 1st row, 1st column....61 = 6th row, 1st column)

Raw Data

File Name: calendar_survey*.iqdat

Data Fields

NameDescription
date Date the session was run
time Time the session was run
subject Participant ID
group Group number
session Session number
build Inquisit version number
q*_response Response given (in assigned values)
q*_latency How much time (in ms) the participant spent on the surveyPage with this particular
question (the last time this particular surveyPage was visited)