Background
Diaries have been widely used in self-report surveys to collect physical activity, travel behavior and time-use data. While it could provide detailed information on patterns of human behaviors, it suffers from several limitations: (a) Scoring such diaries is a very labor-intensive activity and, as such, is very expensive; (b) Raters' objectivity is sometimes a concern when raters are not carefully trained, and (c) It may create a considerable burden on respondents when they are asked to record their activities several times a day and keep the records. In addition, no effort has been to develop and validate a diary that can measure both physical activity and travel behaviors.

Purpose
The objectives of this study are to overcome the above limitations of diaries by developing an E-diary system, which combines voice-recognition and automatic scoring, two advanced technologies and validate it using Armbend and GeoLoggers, two criterion measures based on advanced wireless and GPS technologies.

Methods
There are two stages in this proposed project: Development and Validation. The purpose of the development stage is to develop an E-diary system. The first task in this stage is to develop an E-diary system and the second is to integrate MET scores with the system using the compendium of physical activities (Ainsworth et al., 2000) so that physical activities recorded can be scored.   The purpose of the validation stage is to validate the E-diary system developed.  For reliability, a total of 30 participants will be recruited and they will be asked to collect their physical activity diary data using the E-diary system for 21 consecutive days. Reliability coefficients will be computed using the generalizability theory. For validity, those who participate in the reliability study will also be asked to participate in the validity study, in which they will be asked to record their physical and travel activities by the E-diary system, as well as wearing an Armbend and GeoLoggers, for seven days. The validity coefficients will be computed by correlating the information recorded by the E-diary and those collected by the Armbend and GeoLoggers. Finally, for objectivity, six judges, three experts and three graduate students, will be recruited. They will be asked to rate 50 physical-activity and travel diaries randomly selected from the diaries collected. The kappa coefficients will be computed to determine inter-rater objectivity using the data collected, i.e., classified physical activities.  The agreements among the parties, including the E-diary system, expert judges, and graduate-student judges, will be computed using the kappa coefficients.

Expected Outcome
A reliable and valid E-diary system that can record and analyze physical activity and travel behaviors in an accurate and convenient way.