Environmental Engineering Reference
In-Depth Information
Wetland Problem
or
Observation
Research Questions
Conceptual
Model
Theory
Foundation for Questions
Predictions
Reconsider the original
problem, research
question, theory,
prediction, and research
hypothesis relative to
study results and
conclusions to possibly
modify existing theory,
predictions, and facilitate
testing of additional
alternative hypothesis.
Competing Research
Hypotheses
Statistical Hypotheses
Data Collection
Data Analysis
Predictive Models
Study
Conclusions
Scientific and
Descriptive inference
Publish Results
Fig. 1.1
The process of the scientific method to achieve reliable ecological knowledge (Modified
from Brown and Guy (
2007
). Published with kind permission of
American Fisheries Society
©
2007. All Rights Reserved)
natural systems. Because science is a process, knowledge of natural systems,
including wetlands, evolves over time as previous conclusions are subjected to
further study, and occasionally rejected due to lack of continued empirical support.
Study design expands on the scientific method and has been presented in an
outline or checklist format (Morrison et al.
2001
). Although there are multiple texts
with step-by-step guides for developing study designs (e.g., Cochran
1983
;Cookand
Stubbendieck
1986
;MartinandBateson
1993
; Lehner
1996
), Morrison et al. (
2001
)
characterized the process of study design by 12 discrete steps - (1) question develop-
ment relative to a natural system, (2) development of
1 hypothesis that may answer
the question of interest (testing of competing hypothesis) and associated predictions
should the hypothesis be true, (3) determination of a conceptual study design,
(4) selection of independent and dependent variables, (5) choose appropriate methods
to measure variables of interest, (6) establish acceptable level of precision and
accuracy, (7) pilot study or preliminary data collection to test limitations of original
design and estimate sample size requirements, (8) establish quality/quantity assur-
ance protocols, (9) conduct data collection, (10) perform data analyses and partition
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