Open AccessMethods: Measuring physical activity in public open space — an electronic device versus direct observation
Author(s) -
Milat Andrew J.,
Stubbs Joanne,
Engelhard Susanne,
Weston Peter,
GilesCorti Billie,
Fitzgerald Susan
Publication year - 2002
Publication title -
australian and new zealand journal of public health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.946
H-Index - 76
eISSN - 1753-6405
pISSN - 1326-0200
DOI - 10.1111/j.1467-842x.2002.tb00270.x
Subject(s) - observer (physics) , data collection , physical activity , measure (data warehouse) , significant difference , path (computing) , estimation , statistics , computer science , simulation , medicine , physical medicine and rehabilitation , mathematics , engineering , physics , data mining , systems engineering , quantum mechanics , programming language
Objective: To evaluate the practicality and validity of using infra‐red beam counters (IRBCs) to measure walking path use and overall park use.Method: Direct observation was carried out simultaneously with IRBC data collection in five parks on seven non‐consecutive days during February‐March in 1998 and on matched days in 1999. A second validation study was undertaken in one park in October 1999.Results: The IRBC over‐estimated the observed number of people using walking paths by 14% to 78%. When assessed by path volume, the difference between the IRBC and observer ranged from 10% under‐estimation to 16% over‐estimation. In a more rigorous evaluation of path volume the IRBC under‐estimated the observed count by 20%. The extent to which the IRBC equated with the number of observed park users varied from 69% underestimation to no difference.Conclusion: IRBCs are not appropriate for measuring the number of people engaging in physical activity in parks.Implications: IRBCs cannot replace direct observation for the collection of valid data on physical activity participation in parks. Further research is needed to determine settings in which electronic devices such as IRBCs may provide valid data on physical activity participation.