advantages
The Tangled check projection logic implements a multi-access
identification key (i.e., a key that that allows users to take
different paths through species identification steps based upon
currently available observations), and therefore has all the advantages
that multi-access identifcation keys have over the single-access
identification keys typically found in paperback field guides. As
described in the Wikipedia
article on single-access identification keys,
"A large amount of knowledge about
reliable and efficient identification procedures may be incorporated in
good single-access keys. Characteristics that are reliable and
convenient to observe most of the time and for most species (or taxa),
and which further provide a well-balanced key (the leads splitting
number of species evenly) will be preferred at the start of the key.
However, in practice it is difficult to achieve this goal for all taxa
in all conditions. If the information for a given identification step
is not available, several potential leads must be followed and
identification becomes increasingly difficult.
Although software exists that helps in skipping questions in a
single-access key, the more general solution to this problem is the
construction and use of multi-access keys, allowing a free choice of
identification steps and are easily adaptable to different taxa (e.g.,
very small or very large) as well as different circumstances of
identification (e. g., in the field or laboratory)."
In addition to the typical advantages of multi-access identification
keys, the Tangled check projection logic has other advantages.
- bi-directional
The Tangled check projections are bi-directional. For example, in
addition to being able to project checks from the attribute list
and the geography list to the class list to help with species
identification, Tangled can also project checks from the class list
to the attribute list (to show the attributes of a species) and to
the geography list (to show where a species has been sighted).
- verifiable
The Tangled check projection logic is an implementation of the
basic operations of set mathematics (i.e., and, or, not, xor). If
there are some unexpected results, you can use a text editor to
inspect (or correct) the contents of the sets because they are all
just text files stored in the Tangled phenotypic directory.
- extensible
Is there an attribute you would like to use when identifying
species? If so, create it with the class list's 'select/create
list report' menu item.
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examples
The Tangled check projections are
- operations on sets of species defined in text files in the
Tangled phenotypic directory,
- basic operations in set mathematics (i.e., and, or, not, xor),
and
- implemented in two phases (i.e., the first stage to create an
intermediate set from the specified source sets, and the second
stage to combine that intermediate set with the destination
set).
Here are examples of the use of each of the basic operations in set
mathematics.
The AND operation on source sets is common during species
identification. For example, you can check the species in the class
list that are robin-like AND currently in your Bird Conservation Region
by performing the following steps.
- Switch to the geography list and check just your BCR.
- Switch to the attribute list and check just the passerine shape
attribute and the robin size attribute.
- Switch to the class list and tap the '<' incoming check
projection icon.
- In the automatically displayed check projection options dialog,
check 'attribute list', 'geography list', 'seasonal', and 'source
and' (because the goal is to check the species which are in the
passerine attribute list AND in the robin-size attribute list AND
in the checked BCR's seasonal distribution list). Also check
'reset' and 'dest or' to initially clear the class list checks and
then check the species in the set resulting from the AND operation
of the source sets. Finally, tap the 'OK' button.
The OR operation on source sets is less common than the AND
operation during species identification. However, it can be helpful on
occasions. For example, suppose you want to perform the same check
projection as performed in the AND example (i.e., check the species in
the class list that are robin-like AND currently in your Bird
Conservation Region), except that you live near the border of multiple
Bird Conservation Regions. In that case, perform the following
steps.
- Switch to the geography list and check your BCR and the nearby
BCR(s), and tap the geography list's '>' outgoing check
projection icon.
- In the automatically displayed check projecton options dialog,
check 'class list', 'geography list', 'seasonal', and 'source or'
(because the goal is to check the species that are currently in any
of the checked BCRs). Also check 'reset' and 'dest or' so that the
class list checks are initially cleared before checking the species
that are currently in any of the checked BCRs.
- Switch to the attribute list and check just the passerine shape
attribute and the robin size attribute.
- Switch to the class list and tap the '<' incoming check
projection icon.
- In the automatically displayed check projection options dialog,
check 'attribute list', and 'source and' (note that 'geography'
should not be checked this time because the geography checks have
already been projected to the class list). Also check 'dest and'
(and uncheck 'reset') to so that the intermediate result from the
attribute list gets ANDed with the checks (from the geography list)
already in the class list. Finally, tap the 'OK' button.
The NOT operation is not an option when combining source sets.
However, it might occasionally be useful when combining the results of
the source check logic with the destination list. For example, if you
want to check the hawks that are not currently in your BCR, you could
use the class list's 'check/quick find text' menu item to check the
species names that contain "hawk" and then you could project the
geography list (with your BCR checked) to the class list using the
'dest not' option so the birds currently in your BCR get subtracted
from the "hawk" species checked in the class list.
The XOR (i.e., exclusive or) operation is not an option when
combining source sets. However, it can be particularly helpful when
comparing lists. For example, you could see which species are
different between your BCR and a neighboring BCR by first projecting
your BCR from the geography list to the class list and then projecting
the neighboring BCR to the class list using the 'dest xor' option.
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extensions
Is there an attribute you would like to use when identifying or
comparing species? If so, consider helping create it, with other
Tangled users, using the class list's 'select/create list report' menu
item. Although the Tangled birds of North America guide topic already
has over 300,000 links over which checks can be projected, there is the
potential to document much more. For example, perhaps you are
interested in some of the following sets:
- wingspan (value range),
- mass (value range),
- beak length (value range),
- eye color,
- species with females that sing,
- species that glide,
- species that hop (rather than walk).
Tangled can include documentation of any characteristic or behavior
of species within a guide topic (e.g., birds of North America), and any
relationship between species in different guide topics. It seems
possible that there could eventually be more than one million Tangled
links. Given that the attribute documentation and ecology
documentation are simply text files with species lists, Google's Wave
text collaboration tool seems to be a good fit. If you are interested
in getting in or starting a Google Wave to document a particular
characteristic or behavior, post your interest in the Tangled field guide
users group.
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