Tuhia he haere tonu mō tēnei wāhanga - Ko tētahi o nga whakaaro pohehe noa o te tirohanga pāpori ko e te hononga i waenganui i te tātaritanga whatunga ranei whatunga pāpori tirohanga, me te tirohanga pāpori; e pā ana ratou loosely. Ko te tirohanga whatunga pāpori he momo tuku iho o te tirohanga pāpori. He pai ake te whakaaro i roto i te horopaki o te tirohanga i roto i te pūtaiao pāpori. ara mahere John Snow o te pakarutanga cholera 1854 i Soho
me ngā mahere o te rawakore a Charles Booth i Rānana 1889