Tiling Adhisive on Large Tiles - Is Dot and Dab Enough? Advice and information on tiling and fixing tiles to a variety of surfaces

[Gloriasgarden]

I am having a new bathroom built and the tiler has started tiling. Tiles are 60 x 30cm and are porcelain. He has applied the adhesive in 5 blobs on the back. When I have done tilling in the past I have spread adhesive over the whole tile with serrated spreader. Is he doing it wrong?
Gloriasgarden

[welsh brickie]

he will tap the tiles in place with a rubber mallet so the adhesive will cover the tile when squashed, not the way I would do it though