“…allergen (Taylor & Shivalkar, 1971;Britton et Many investigators have relied on subjective Connell, 1979 (Todd et al, 1975; nasal provocation and measurements of nasal Wong et al, 1981), whilst others have used patency (Kern, 1981;Clement, 1984) (Graamans, 1981;Wihl, 1983) making comparisons of the results obtained from different laboratories difficult. Furthermore, the repeatability and reproducibility of these methods has rarely been the subject of detailed study.…”