digraph test {
   rankdir = "LR"
   fontname = "Helvetica"
   node[fontname = "Helvetica"]
   edge[fontname = "Helvetica"]
     structure [label = "What\nis\nstructure?",  shape=diamond]
     small  [label = <
         
          sumlog  (Fisher)
          minimump  (Tippett)
         
     >]
     large  [label = <
         
          sump  (Edgington)
          maximump
         
     >]
     equal  [label = <
         
          sumz  (Stouffer)
          logitp
         
     >]
    structure -> small [label = "Emphasise small p-values"]
    structure -> large [label = "Emphasise large p-values"]
    structure -> equal [label = "Emphasise p-values equally"]
}
