In this project, I have three polygons, see the image below

 1. `"Polygons_From"`, includes input attributes, i.g. `"Value_1"`, `"Value_2"`, `"Value_3"`, and `$area` for each quadrate (on the image there are two types of them).
 2. `"Polygons_To"` polygons for which new values `"Value_1_new"`, `"Value_2_new"`, `"Value_3_new"` need to be defined
 3. `"Border"` defines an area where the calculation should be done.

[![My_input][1]][1]

My task is simply to transfer values from `"Polygons_From"` into `"Polygons_To"` based on a certain aspect. At this point, I am considering `$area`. But perhaps there are better approaches that will lead me to a much more efficient output.

So, I am asking for a recommendation regarding the technique/workflow that can be applied in QGIS 2.18. Shall I consider only `$area` or there are some other criteria?

Moreover, I looking forward to finding some papers that may improve my general understanding of the methodology.

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**References:**

 - [Calculating polygon area inside another polygon in QGIS](https://gis.stackexchange.com/questions/240511/calculating-polygon-area-inside-another-polygon-in-qgis)
 - [Calculating area of polygon inside region?](https://gis.stackexchange.com/questions/120462/calculating-area-of-polygon-inside-region?rq=1)
 - [Calculate proportional area of polygon within another layer's polygon](https://gis.stackexchange.com/questions/214893/calculate-proportional-area-of-polygon-within-another-layers-polygon?rq=1)

  [1]: https://i.sstatic.net/xE5dv.jpg