-4- 



Dlameter Class Size . INVENT assumes that trees will be grouped Into 

 diameter classes. The size of the class Is up to the user within the follow- 

 ing limitations. The class size must be a whole number. The smallest diameter 

 class allowable is the class size; i.e., if the class size is 2 in. then the 

 first class must be 2 inches. All other diameter classes must be integer 

 DHjltiples of the class size. The maximum diameter class must be less than or 

 equal to 40 inches. 



Confidence Level . INVENT uses the 95 percent confidence level as a 

 default. Using this level, there is only a one in twenty chance that the 

 true volume will be outside the confidence interval computed by INVENT (Cf. 

 Freese 1967, p. 11). This is the most common confidence level used in 

 forestry in the Northeast. If the user wishes to use a different level, he 

 may specify that level as long as it is in the range from 65 percent to 

 99 percent. 



Tract Description . A tract description of up to 70 characters should be 

 specified for the forest. This description will be printed at the top of 

 each page of the combined compartment summaries. 



For each compartment within the forest, the forester must supply the 

 information requested on the INVENT Compartment Information Form (Appendix A, 

 page 49). This information includes: 



1. Compartment name and/or description. 



2. Sampling method and sample unit size. 



3. Tree height measurement units. 



4. Tree top specification. 



5. Whether or not the heights of all volume trees were 

 measured. 



6. Size of compartment in acres. 



Compartment Name . A compartment name and/or description should be 

 specified for each compartment. The description may be up to 70 characters 

 in length and is printed at the top of each page of the compartment output 

 tables. 



