ðɪs mˈeɪ lˈiːd tə sɪɡnˈɪfɪkənt sˌɪstəmˈæɾɪk dˈɪfɹənsᵻz ɪnðɪ ˈaʊtkʌm ʌvðə kəntɹˈoʊl ɡɹˈuːp, əbskjˈʊɹɹɪŋ ðə ɹɪzˈʌlts ʌvðə stˈʌdi ænd θɹˈɛʔn̩ɪŋ ðɛɹ vælˈɪdᵻɾi.
This may lead to significant systematic differences in the outcome of the control group, obscuring the results of the study and threatening their validity.