Answer types
For each question you decide what shape the answer should be stored in. The called person answers freely, in their own words — the type says what should be taken out of those words.
Three answer types, and the three shapes they are shown in.
There are three, and the results look different with each.
Yes/No
For questions answered by confirming or denying: Did you take all your medicines today? Does your head hurt today?
Yes or No is stored. The results appear as a grid of coloured tiles —
one per call, so a run is visible at a glance.
The summary shows the last answer, the most common answer and the counts of both.
Numeric
For measured values: What was your body temperature this morning? What was your upper blood pressure reading today?
A number is stored. The results appear as a chart over time, and the summary works out the minimum, maximum and average.
Ask about one figure per question and say what units you want — why, is on Wording a question.
Text
For everything that fits neither a number nor a yes/no: How did you sleep last night?
What the person said is stored, condensed into a sentence. The results appear as a list of answers, newest first.
A text answer cannot be added up or averaged. Consider whether the question could be put so that it yields a number or a yes/no — those are far easier to work with.
When no answer can be extracted
Not every call ends in a value, and the service does not paper over it. The question's history shows these cases:
An ambiguous answer comes with a quotation — verbatim what the called person said. It often shows that the person answered perfectly well and it simply could not be written into the requested type.

"I haven't measured it yet today, the thermometer is by the bed and I was in a hurry this morning." An answer it is; a number it is not.
It is also the best signal that a question is badly put. A few ambiguous answers in a row usually mean you are asking about two things at once, or not saying what units you want.
Changing the type
The answer type of an existing question can be switched (the pencil in its row). Earlier answers are not recomputed, though — they stay stored in the type they were created in. For a question that has already collected something, it is cleaner to create a new one.