Often in conducting multi-centered (multiple locations) Randomized-Controlled Trials, individuals are recruited for a study from a study site until there are enough individuals for the study.  For example, in a COVID-19 Phase 3 randomized-controlled trial, a clinic might recruit high risk healthcare workers non-randomly (i.e. Nurses working in the Emergency Department) for the study.  Recruitment of individuals continues on an ongoing bases until a quota (target) number of study subjects is achieved.  What kind of sampling is this?

Researcher are conducting a household survey where they randomly select a city neighborhood and then survey every 5th house on the street until they reach their target sample size. What type of sampling is this? 

Due to the 15th century Italian building boom, ___________ was the only northern European city as large Venice, Naples, or Milan.

The only Italian city that was strong enough to keep its autonomy well into the 18th century was _______.

Production of iron during this period also rose rapidly.  This fed the construction boom.  The chief reason for this explosion was

Which of the following materials are commonly found major in Medieval buildings? 

The Sophia Hagai “seems to float on air” mainly due to what innovation?

Most castle walls were insulated with _________________________________________.

The _________________________________ method of determining the size of the footprint of a building estimated the footprint size of the Cathedral in Bern, Switzerland (left) to within 60 mm before it was built. 

Most cathedral failures came from _____________________________.