Dot Sampling Research Center
 2 Basic idea/technique of
the dot sampling method
1 Home    2 Basic idea of the method    3 Materials issued by the Center  4.Definition of area    5 Question and Answer on the site    

2.1 Dr. Frank Yates says
 Dr. Frank Yates describes as follows;
If accurate large-scale maps showing the field boundaries are available, the point method of sampling is very suitable for crop surveys in which contact with the farmer is not necessary. The fields with then act as sampling units, and selection will be with probability proportional to size. (Frank Yates, SAMPLING METHODS FOR CENSUSES AND SURVEYS, 1949, P.82)

The dot sampling method comes from this idea. The advent of Google Earth has made this idea a reality for us.


2.2 Basic idea of the dot sampling survey method.

   
 Step 1  


This is a map and target areas for your area survey. 
 Step 2  


You put a dot-grid plate on the map. 
 Step 3  

You count the number of dots by category (collar). 
 Step 4  


You  try various analyzes.


2.3 Procedure of the Dot sampling method for a planted area survey  

Based on the basic idea mentioned above, we designed the procedure of the dot sampling method for a planted area survey in the Figure below.
It consists of four steps. The first step is “dot sampling”, the second step is “preparatory survey”, the third step is “field survey” and the fourth step is “estimation”. To realize the idea, especially in the first step, we developed two techniques using Excel VBA. One is to generate the systematic random sampling dots on Excel sheet and the other is to put those sample dots on Google Earth.
 

Details are shown on pages 4-9 of the next report, please see.  Dot Sampling Method for Area Estimation