The use of wine tasting descriptors allows the taster to qualitatively relate the aromas and flavors that the taster experiences and can be used in assessing the overall quality of wine. Wine writers, like Karen MacNeil author of The Wine Bible, differentiate wine tasters from casual enthusiasts; tasters attempt to give an objective description of the wine's taste (often taking a systematic approach to tasting), casual enthusiasts appreciate wine but pause their examination sooner than tasters. The primary source of a person's ability to taste wine is derived from his or her olfactory senses. A taster's own personal experiences play a significant role in conceptualizing what he or she is tasting and attaching a description to that perception. The individual nature of tasting means that descriptors may be perceived differently among various tasters.