The purpose of conducting the resection method in plane table surveying is to determine the location of the instrument. Resection is a technique used to locate the position of the plane table in the field, without the need for any reference points or known coordinates. It allows the surveyor to establish the position of the table using only observations of distant objects in the field of view.

Resection involves observing a minimum of two prominent features or points in the field, and then plotting their positions on the plane table. These points should be well distributed in the field, preferably at a distance apart from each other. The more distant the points, the better the accuracy of the resection.

The process of resection can be summarized as follows:

1. Set up the plane table at an unknown location in the field.
2. Orient the table using a magnetic compass or other suitable method.
3. Observe two or more prominent points in the field through the sights of the table.
4. Record the angles between the line of sight to each point and a reference line, such as the magnetic north.
5. Plot the positions of the observed points on the plane table using a scale and protractor.
6. Draw lines from the observed points to the corresponding positions on the table.
7. The intersection of these lines will give the location of the plane table.

By accurately observing and plotting the positions of multiple points, the surveyor can determine the location of the instrument with a high degree of precision. This allows for the subsequent plotting of details or surveying of the surrounding area.

In summary, the purpose of conducting the resection method in plane table surveying is to determine the location of the instrument in the field. This technique provides a means of orientation and allows for accurate plotting of details and surveying of the surrounding area.