APPENDIX A 

 General Explanation 



Page 



DATA COLLECTION A-1 



DATA PROCESSING A-1 



MAJOR DATA CHANGES A-1 



FOLLOW-ON SURVEYS, SPECIAL CENSUSES, AND 



RELATED PUBLICATIONS A-1 



DEFINITIONS AND EXPLANATIONS A-2 



FARMS CLASSIFIED BY SPECIFIED CHARACTERISTICS A-4 



CENSUS NONSAMPLING ERROR A-4 



DATA COLLECTION 



Method of Enumeration 



The census of agriculture was conducted by direct 

 enumeration beginning in April 1 990 in conjunction with the 

 population and housing censuses. On the last page of the 

 population and housing questionnaire was an agriculture 

 screening section. The enumerator was required to com- 

 plete an agriculture questionnaire when a "yes" answer 

 was received to any one of the five screening questions. 



Questionnaire 



The questionnaire for the 1990 Census of Agriculture in 

 the Northern Mariana Islands was prepared by the Agricul- 

 ture Division, Bureau of the Census, in cooperation with 

 the Government of the Northern Mariana Islands. 



The content of the 1990 census questionnaire is similar 

 to the 1 980 questionnaire. Quantity sold and value of sales 

 were added to the crops and livestock sections. Other 

 additions and deletions were made based on discussions 

 with the Government of the Northern Mariana Islands and 

 with respect to published tables in the 1980 census. 



Followup Procedures 



An enumerator was instructed to visit a farm up to three 

 times. If no one was available to complete the question- 

 naire, the case would then be given to the supervisor. If all 

 attempts to obtain the information from the farm operator 

 failed, the information might then be obtained from a 

 neighbor or by observation of the place. 



DATA PROCESSING 



The processing was done in the Agriculture Division at 

 the Bureau of the Census. Each questionnaire was edited 

 and coded prior to being keyed and tabulated. The ques- 

 tionnaires were examined for accuracy, consistency, and 



completeness. Errors in computations and in units of 

 measure, inconsistencies, and misplaced entries were 

 corrected. Incomplete reports were adjusted on the basis 

 of related information on the same form or on question- 

 naires for nearby farms of similar type and size. 



After all questionnaires had been reviewed, the data 

 were keyed and subjected to a detailed item-by-item 

 computer edit. The edit performed comprehensive checks 

 for completeness and consistency. Inconsistencies identi- 

 fied by the edit were corrected by subject matter special- 

 ists and reedited. The data were then tabulated by the 

 computer for analysis. Following necessary corrections, 

 the data were retabulated for final publication. 



MAJOR DATA CHANGES 



Prior to each agriculture census, the Bureau of the 

 Census reviews the content of the census forms to elimi- 

 nate questions no longer needed, identify new items 

 necessary to meet user needs, and to better describe the 

 agriculture situation in the Northern Mariana Islands. Data 

 requests are solicited from government agencies in the 

 Northern Mariana Islands. The following changes were 

 made to the 1990 questionnaire: 



• Additions: 



- Information on landlords 



- Ornamental plants and nursery crops 



- Chicken eggs value 



- Quarts of milk 



- Quantity and value of sales in the crops and 

 livestock sections 



• Deletions: 



- Coffee 



FOLLOW-ON SURVEYS, SPECIAL CENSUSES, 

 AND RELATED PUBLICATIONS 



In addition to the 1990 Census of Agriculture for Amer- 

 ican Samoa and the Commonwealth of the Northern 

 Mariana Islands, the census of agriculture program includes 

 the 1987 Census of Agriculture for the 50 States, Puerto 

 Rico, Guam, the U.S. Virgin Islands, the 1988 Farm and 

 Ranch Irrigation Survey, the 1988 Agricultural Economics 

 and Land Ownership Survey, and the 1988 Census of 

 Horticultural Specialties. 



Additional publications of the 1987 Census of Agricul- 

 ture data include the Agricultural Atlas of the United States 

 (previously called the Graphic Summary), Coverage Eval- 

 uation, Ranking of States and Counties, Government Pay- 

 ments and Market Value of Agricultural Products Sold, and 

 ZIP Code Tabulations of Selected Items. 



1987 CENSUS OF AGRICULTURE 



APPENDIX A A-1 



