This survey is using self-assessed cups - without providing a cup size or any guidance. Specifically, a survey asks users "How many cups of coffee do you drink

This survey is using self-assessed cups - without providing a cup size or any guidance. Specifically, a survey asks users "How many cups of coffee do you drink a day?" with no other context. So, "cups" for this study is whatever the respondent considers a cup. For most people, that's going to be at least 8 ounces and probably 8-12 oz. From the full text (https://ore.exeter.ac.uk/repository/bitstream/handle/10871/126392/FINAL_AcceptedManuscript_NNS.pdf https://ore.exeter.ac.uk/repository/bitstream/handle/10871/1...), here's how the intake is described: > Habitual coffee intake was self-reported as cups per day, as part of the touchscreen questionnaire at baseline with the question “How many cups of coffee do you drink a day?” (38). Participants were asked to include decaffeinated (decaf) coffee intake in their response. Decaffeinated consumers were identified from response to the question “What type of coffee do you usually drink?”. Coffee consumption was grouped in seven categories, including non- drinkers, decaffeinated coffee drinkers, and caffeinated coffee drinkers consuming <1 cup/day, 1-2 cups/day, 3-4 cups/day, 5-6 cups/day and >6 cups/day. “Coffee drinkers” in the text refer to participants who report intake of caffeinated coffee. For sensitivity analyses we constructed separate indicators restricting the data to decaffeinated coffee drinkers and according to tea consumption, using intake categories as above"