A comparison of work-sampling and time-and-motion techniques for studies in health services research.
OBJECTIVE
This study compares results and illustrates trade-offs between work-sampling and time-and-motion methodologies.


METHODS
Data are from time-and-motion measurements of a sample of medical residents in two large urban hospitals.


METHODS
The study contrasts the precision of work-sampling and time-and-motion techniques using data actually collected using the time-and-motion approach. That data set was used to generate a simulated set of work-sampling data points.


METHODS
Trained observers followed residents during their 24-hour day and recorded the start and end time of each activity performed by the resident. The activities were coded and then grouped into ten major categories. Work-sampling data were derived from the raw time-and-motion data for hourly, half-hourly, and quarter-hourly observations.


RESULTS
The actual time spent on different tasks as assessed by the time-and-motion analysis differed from the percent of time projected by work-sampling. The work-sampling results differed by 20 percent or more of the estimated value for eight of the ten activities. As expected, the standard deviation decreases as work-sampling observations become more frequent.


CONCLUSIONS
Findings indicate that the work-sampling approach, as commonly employed, may not provide an acceptably precise approximation of the result that would be obtained by time-and-motion observations.
Finkler
S A
SA
Robert F. Wagner Graduate School of Public Service, New York University.
Knickman
J R
JR
Hendrickson
G
G
Lipkin
M
M
Thompson
W G
WG
D015982:Bias; D016001:Confidence Intervals; D003625:Data Collection / Q000379:methods; D006291:Health Policy; D006302:Health Services Research / Q000379:methods*; D006786:Hospitals, Urban / Q000458:organization & administration; D006801:Humans; D007396:Internship and Residency / Q000458:organization & administration*; D007587:Job Description; D008505:Medical Staff, Hospital; D015203:Reproducibility of Results; D012494:Sampling Studies; D013996:Time and Motion Studies; D014481:United States; D014937:Work