With the growth of survey research came improvements in questionnaire design and question construction. During the 1930s sampling became a serious methodological issue
an advance that followed by or was between the 1920's and 30's during the Harlem renisistance
an advance that followed by or was between the 1920's and 30's during the Harlem renisistance
Vitamin E was discovered, and so was penicillin and insulin and the first use of a valvulotome.
1920
National Bureau of Economic Research was created in 1920.
Scott Polar Research Institute was created in 1920.
Boyce Thompson Institute for Plant Research was created in 1920.
Automobiles and airplanes were made for transportation. Radios and movies came out as well, thus improving communication.
i dont know but check on google they have good research programs
http://www.scribd.com/doc/1768/Some-stories-about-popular-inventions-and-discoveries This is a good article describing a number of technological advances that led to things we use today. For example, the modern microphone was invented in 1920.
The average life span for people in the US from 1920 to 1980 increased from around 54 years in 1920 to approximately 73 years in 1980. Advances in medicine, public health initiatives, improved living conditions, and better nutrition all contributed to this increase in life expectancy over that period.
While doing research on a project for the 1920's, I read somewhere that it was because of the flapping movement of their arms while doing the popular 1920's dance, the charleston. hope this helped :)