profession such as doctor, lawyer, or teacher. Exchange 

 work or work done by the operator in exchange for 

 comparable work done by someone else was not to 

 be reported. 



FARMS CLASSIFIED BY SPECIFIED 

 CHARACTERISTICS 



Tables 21 through 24 present detailed data for farms 

 classified by specified characteristics — tenure of operator, 

 size of farm, age of operator, and value of agricultural 

 products sold. 



Farms by tenure of operator— Farms were classified 

 by tenure of operator on the basis of information reported 

 for land owned, rented from others, or worked on shares 

 for others. During the processing operations, each ques- 

 tionnaire was coded to indicate whether the farm operator 

 was a full owner, a part owner, or a tenant. The various 

 classifications of tenure are: 



• Full owners operate only land they own. 



• Part owners operate land they own plus land they rent 

 from others. 



• Tenants only operate the land they rent from others 

 or work on shares for others. 



Farms by size— Farms were classified by size on the 

 basis of the total land area determined for each farm. 

 According to the census definition, a farm is essentially an 

 operating unit, not an ownership tract. All land operated or 

 managed by one person or partnership represents one 

 farm. In the case of tenants, the land assigned to each 

 tenant is considered a separate farm even though the 

 landlord may consider his/her entire land holding to be 

 one unit rather than several separate units. 



Farms by age of operator — Farms were classified by 

 age of operator on the basis of information reported to the 

 enumerator that was entered on the report form. The 

 operator's age was classified into one of the age groups 

 found in table 23. 



Farms by value of agricultural products sold — Farms 

 were classified on the basis of the total value of agricultural 

 products sold. The total was obtained by adding the 

 reported values of all products sold from the farm. The 

 value of vegetables, field crops, fruits and nuts, nursery 

 and ornamental plants, livestock, poultry, fish, and eggs 

 was obtained from the operator at the time of enumeration. 

 These values were classified into one of the groups found 

 in table 24. 



CENSUS NONSAMPLING ERROR 



All data originated from a complete enumeration and, 

 therefore, are not subject to sampling variability. However, 

 the data are subject to nonsampling errors. Nonsampling 

 errors can be attributed to many sources: 



• Inability to identify all cases in the actual universe. 



• Inability or unwillingness on the part of respondents to 

 provide correct information. 



• Definition and classification difficulties. 



• Differences in the interpretation of questions. 



• Errors in recording or coding the data obtained. 



• Other errors of collection, response, coverage, and 

 estimation for missing or misreported data. 



The accuracy of these tabulated data is determined by 

 the joint effects of the various nonsampling errors. No 

 direct measures of these effects have been obtained; 

 however, precautionary steps were taken in all phases of 

 data collection, processing, and tabulation of the data in an 

 effort to minimize the effects of nonsampling errors. 



A-4 APPENDIX A 



1987 CENSUS OF AGRICULTURE 



