"time span of observation" is a perfectly valid phrase in English.
You can use it whenever you want to refer to the duration of an observation period. For example: "We examined the impact of the new policy over a six-month time span of observation."
This tendency is similar on all trial plots although the time span of observation differs between four (SAN653) and seven years (GYO651).
These results, obviously relevant for any policy analysis, have been possible through the proposed analysis although the time span of observation was only five years: it is possible that longer periods of observation could offer even more interesting results.
Our data, demonstrating for the first time a reduction of the IL-4 producing cells in professional athletes over a long time span of observation, could be in agreement with the data coming from the murine studies previously cited.
Identifying depression in administrative data is challenging: it is an episodic condition that changes over time, so a different time span of observation may have a profound effect on results.
In the study of the dust-scattered halo of a GRB, the X-ray light curve of the source can be treated as an ideal delta function because a GRB duration is typically in the range of several seconds, a negligible value compared to the time span of observations and the travel time in the interstellar medium.
The time span of observations was 55 years for Denmark, Finland, Norway and 50 years for Sweden.
In addition, due to the perspective and time span of the observation, we did not assess direct costs, such as rehabilitation and long-term care.
When looking at the historical evolution of the spatial light Gini coefficients, we saw a gradual increase over the time span of our observations, which is the past 17 years.
The reduced time span of the patients' observation time in the control group might be due to the lack of postoperative complications in this group who did have follow-up examinations in the department.
A data set of ∼400 CCD observations covering about the same 6 years time span of the ∼12,000 ICQ selected total visual magnitude observations were used in the analysis.
However, for observation purposes, a time span of five transaction days, which is equivalent to approximately one week, was selected.
