**Guide Book**

**Second title**

The **Guide Book** has been developed by Bob Giles (starting in 2005) to suggest things he might like to say or to which to point for employees, members, and cooperators of **Rural System**. Comments range from personal philosophy, statements with which he agrees, and things he calls "hints"

They may some day be organized, but for a start, they have just been added when and where he wanted to. Hopefully participants will use them, be taught their implications, and ask questions about them in training sessions and elsewhere.

**Credo****Decent Work****Models**- In our work, asimplifies a thing used in order better to appreciate it, understand its purposes or uses, and to understand how it works. It may suggest the past (or rely of knowledge of it) and most likely will be used to suggest the future. While a poem may be a word model and there are useful art and physical models, we move as rapidly as possible to algebraic models, then to putting these into computer code with outputs as word messages and two- and more-dimensional pictures and moving multidimentional images.*model***Statistical Range**- Work past the central tendency statistics (mean, median, mode) and concentrate on the range ( there being several definitions, just ponder the extreme values or, at least the mean value plus or minus more than three standard errors from the mean. Always reconsider a central tendency statistic like the standard deviation with the often-real value that occurs in nature of zero, no matter what the statistic says. Use range limits in models.*limits***Expected Value**- Net value is well known as total gains minus the costs. Expected value is less well known and needs to be unified with "balanced estimates." Expected value is the product of a market value for an item and the probability of having a desired product. Buying 100 apples for $10 suggests their value is 10 cents each. If you expect half to be bruised and rotten by the time of devivery, their value is 20 cents ... the probability of selling a whole apple is 0.5. Staff need to continually use expected value. That can be combined with balanced estimates.What if you have complete faith in a relationship of

**Z = A**^{1.3}You want to know

**Z**, so you measure very carefully and precisely A. Then you must estimate or guess at the exponent (as you might for the rate of change in growth or interest rates, etc.). Of course you include knowledge of limits and the possible range of values, but is it reasonable to be very precise (usually at very high costs - time, labor, storage, summary and analyses, equipment use, etc.) in one part of an equation when gross estimates are all that are available for the other? Balance is needed. We work with the expected value of**Z**, realizing that some numbers cannot likely ever be improved significantly and must always be estimated (e.g., the future value of the national average bank interest rate). Thus combining numbers in a model must be done in a balanced way. We need great precision (high probability), but it comes at great cost. It must be sought for reasonable price - dependent on the context, the probability associated with the other numbers in the model (or the other apples in the box).- Chapter 3 of
*Rural System …Just Dreaming* - Chapter 4 of
*Rural System …Just Dreaming*

*Perhaps you will share ideas with me about some of the topic(s) above .*

**Home****Rural System**

Glossary

Robert H. Giles, Jr.

July 3, 2005