R G OderwaldStatistics for Forest Inventory
Statistics is not a popular subject. Most people asscociate it with boring calculations, dry as dust presentations, and confusing answers.
But, statistics is how car, life, and any other insurance rates are set, how unemployment is calculated, how publishers decide what books to publish, how your car seat is shaped, and a million other things. You can't avoid statistics. Either face it or hide under the bed. Statistics isn't going away.
Statistics is particularly useful in forest inventories. The way we collect data as we go is an advantage few others have. We can watch our answers become our answers.
Foresters bet, and they bet big. Foresters routinely place bets on timber sales that a banker would need a committee to approve. Anyone placing bets this big had better know the odds.
Bets and odds are what Statistics for Forest Inventory is all about. There are only a few simple formulas and a computer can handle them. The important part isn't how to get the bets, but what to do with them once you have them.
Statistics for Forest Inventory Outline
- Average
- Bets
- Stakes and Odds
- Calculation
- Advantage of Calculating the Average in a Cruise
- When does the average stop changing
- Does the rest look like what I have already seen
- Standard Devaition
- Measure of difference between plots
- Mesurement units
- Effect of Sample Size
- Advantage of calculating standard deviation in a cruise
- When does the standard devaiation stop changing
- Betting on the next plot
- Statistics vs reality
- Coefficient of Variation
- Calculation
- Combines average and standard deviation
- Removes measurement units
- General CV size
- Bet on the next plot
- Standard Error
- Standard deviation of averages
- Calculation
- Bet on next average
- Effect of sample size
- Comnfidence Intervals
- Percent bet
- Equivalent bets
- Limites with values
- Limits as percentages
- Margin of error
- 68% and 95% bets
- Median
- Calculation
- Less affected by extreme values as average
- Confidence interval for median
- CI for median vs Ci for average
- Quartiles and Interquartile Range
- IQR vs standard deviation
- Sample Size
- Most often asked question
- Old methods: fixed grid and percent cruise
- Variability of stand
- Expected error
- Allowable error percent
Approved for 6 Class 1 CFE credits by the Society of American Foresters