 |
 |
|
|
|
|
|||||
 |
 |
 |
|
 |
 |
 |
||||
|
A statistical summary is needed to provide information to meet the survey objectives. The design of the survey determines the way you analyze the data. They are not independent of each other. Communicating results is the last important step in this process. Reports, graphics, and tables can be used to summarize the results of a survey, but care must be used in the presentation. Improper use of graphics can alter the perception of differences between subpopulations, or regions. A poorly written report can have a detrimental effect on a carefully planned survey.
However, the data needs to be verified and
validated before any serious data summary should start. Although
the
verification and validation
process may seem to
possess similar attributes, the difference between them can be seen
when
understanding the individual processes. Data
verification is the first of the two evaluations to
occur, being
performed by all personnel.
The ultimate goal of data verification is to
ensure and
document that the reported results reflect what was actually done. Although there may be a need for an external
data verifier, that does not relinquish the responsibilities of the
sample
collectors and laboratory analysts to verify their own data. Data
verification should be occurring at each
level, by multiple personnel. The data
verification process tends to be predominantly an internal practice for
the
field and laboratory staff; however, depending on the project, it is
not
uncommon to have an external verifier. Whether or not the current verifier is an
external or internal member, it is
crucial that
they are familiar with the programs requirements. Understanding
the purpose of the study and
all protocols will ensure that the data verification procedure will be
effective.In addition to understanding
the material, it is important to have all protocol documentation easily
accessible. Developing
environmental data of any kind involves the production of documentation
and
records, from daily field logs to electronic records; data verification
is no
different. However, first, the verifier
should identify the source and location of all records produced,
including all
calculations performed on the input data. In
addition, the verifiers should determine the criteria
or
specifications against which the records will be compared.
The records obtained may be produced by
multiple personnel with different formats, although they should be
following
the records-keeping procedures, the verifier should review the formats
and get
comfortable with the individual styles.
The
five
steps to be verified are the: sample collection, sample receipt, sample
preparation, sample analysis, and records review, and are discussed on
subsequentt pages. |
||||
|
|
|
|
|
|
|
|||||
