Numeric Value Scores

This page last modified on 15 June, 2006

Lucid3 provides means to encode numeric values as value ranges with extreme lower and upper limits of the range treated as rarely occurring, while the normal lower and upper limits are intermediate. Thus such a numeric score might typically be [2:5:10:14] where:

• values in the range 5 through 10 occur normally
• values in the range 2 through 5 occur rarely
• values in the range 10 through 14 occur rarely

The distinction between Features which occur normally, and those that only occur rarely, is used by the Player to rank the order in which matching Entities are presented in sorted lists. Thus far, I haven't found a strong reason to use this capability in connection with identifying Astereaceae species. If interested, I suggest that you check the Help ["?" icon] documents when using the Player.

In a case where just one value applies, such as "Number of Ligules: always 5", the numeric score in the key will be [5:5:5:5].

Of more significance is the manner in which numeric values should be scored if described in The Jepson Manual (TJM) as, for example, either:

• "> 10" meaning 10 or more
• "< 6.5" meaning 6.5 or fewer

While the Player will accept your input of something like "<4.5" to indicate you want to match all plants which match a numeric score of 4.5 or less, it isn't clear how a TJM number value of "<4.5" should be interpreted for scoring the key. While logically you could interpret this to mean that even a value of zero ("0") should be matched in a search, that typically isn't realistic for measures such as Stem Length, or Width of Involucre. In fact the Lucid Builder, used for scoring the key, will not accept "<4.5" for a numeric value.  But I concluded that a TJM value such as "<4.5" should be given a numeric range score of [0:0:4.5:4.5], as code to express this meaning, and that's how you will see such a score listed on the Profile pages.

Similarly, a TJM description such as "> 10" doesn't really mean "any value greater than 10" since realistic upper limits must apply - TJM just doesn't tell you what they are. I've scored this situation with the range [5:5:999:999] where for practical purposes the "999" stands for infinity, yet it is accepted as a number by the Builder for use in the key.

Finally, in some cases it may be useful for you to know that the Player will accept, for input of a number value, either a single number such as 3.5, or a range such as 2-6.5 (meaning any value from 2 through 6.5). See the Player Help page regarding precision of such numbers, if that issue is important to the identification of interest to you.

A final point, which may be of significance in some searches using the key:  Numeric scores are considered Features (not States) in Lucid. Thus, you cannot logically produce an Entities Remaining list containing both species with ">20 Ligules" OR "Many Ligules". (But you could produce one with "Few" OR "Many" Ligules.) The Entities Remaining include only items which match one-OR-more checked State values within a single Feature, thus indicating that the Feature is Present for matching purposes. But each-AND-every other checked Feature must be Present in the final list.

-- Ken Bowles