Pulse Asia's survey methodology is typical of a private survey firm's approach to sampling given limited resources but still able to make some measurable conclusions.
I am not an agent of Pulse Asia, but Pulse Asia has technical notes able to be understood by people exposed to survey sampling methods.
1st, Pulse Asia's domain of concern in studying to have measurable accuracy with sampling is the four geographic areas: NCR, Luzon w/o NCR (termed Balance Luzon), Visayas, and Mindanao, each of the four alloted 300 samples each, thus 1,200 samples.
It is difficult to believe the curve of new confirmed cases per day, because It is highly susceptible to the limitations of @DOHgovph in terms of data management and case validation. Look at the curve of cases by onset of symptoms
1/n
Ignore the point the last portion where the line drops, because again, data delays in validation and testing.
As one can see, the cases have seemingly growing at an increasing rate, bar again the last 9 days or so of the data.
Flattening of the curve entails: 1) a basis on a reference curve of no interventions or the worst scenario, and 2) knowledge of the healthcare capacity
3/n