Why is deception acceptable in some psychological investigations?

An epidemic is a large and localized outbreak of a sickness or disease.  a pandemic is a large global outbreak of a sickness or disease. 

Depression is lifelong, though you can get medication to with it. the difference between sadness and depression is that sadness lasts a little bit, depression last a long time and it goes on and off. people usually get depression through experiences they have been through, or genetics.

Answerunderstanding what advocacy means and looks like in action;

Answermaintaining a three day food diary in a diet log;