Please help with 2 questions!

1. You are doing a study of public perception of acupuncture. You can afford to collect survey data on 400 Portland residents, but one complication that occurs to you is that perceptions may be very different among those who have actually experienced acupuncture, and if the fraction of such people in the general population is small, you won't have enough observations on them to draw a valid inference on whether they actually do have a different perception, and how that affects the broader average. (a) One solution is to redefine the population and adjust the sample accordingly. Explain. (b) Another is to take steps to ensure you have enough observations on experienced acupuncture patients despite your resource constraint. Explain.

2. You are interested in the effect of mask mandates in the schools on community spread of Covid. You locate a city that is half in one state and half in another. In the first state there were mask mandates during the time period you are studying; in the second there weren't. Under what circumstances might this be considered a pseudo-experiment?