Edward jenner’s smallpox inoculation experiment was based on an observation by a dairymaid that she could not get smallpox because she had already had cowpox. how did jenner form his hypothesis from this observation? he asked what would happen if he deliberately inoculated someone with cowpox fluid from another person. he tested different existing inoculations to see which one was most effective in preventing smallpox. he observed dairymaids milking cows with cowpox to see if the statement was true before forming a hypothesis. he drew a conclusion about cowpox infection based on the comment he overheard from the dairymaid.