How's it going?

Person asking	Probable motive for asking	The best way to answer (based on trial and error)
Stranger	Wants to make small talk	Going great, has its ups and downs. How's your day been?
Mother	Wants to understand and take an interest in what I'm doing	Pick a small part of my PhD work to explain using bakery-related analogies
Competitor	Wants to find out if they're doing better than me yet	Going great.
Friend	Wants to encourage me or offer advice if they can	Discuss current problems
Supervisor	Wants to know how it's going	Describe exactly and truthfully what I am currently doing in one sentence or less