Match each example of a study to the type of method used. researchers develop a survey and ask the same questions to 40,000 randomly selected people. researchers interview or survey the same 1,000 families every 5 years over a 40-year period. researchers conduct long interviews with open-ended questions with 40 couples. researchers observed 15 families in their homes over a period of 1 year. researchers survey family members on how many hours per week they spend doing various tasks or ask them to keep a diary of what they do every 30 minutes over an entire day over a period of a week.

1. Researchers develop a survey and ask the same questions to 40,000 randomly selected people. - Sample Survey

Sample surveys involve using a subset of the population that is randomly selected as the basis for the research.

2. Researchers interview or survey the same 1,000 families every 5 years over a 40-year period. - Longitudinal survey

In a Longitudinal survey, participants are observed and studied at regular intervals over a period of time which can either be long or short term.

3. Researchers conduct long interviews with open-ended questions with 40 couples. - In-depth Interviews

In-depth interviews aim to find out as much on a topic as possible and as such can take some time to complete. Questions are usually open ended so subjects can express themselves fully.

4. Researchers observed 15 families in their homes over a period of 1 year. - Observation

Observational study involves observing the subjects often in their natural settings.

5. Researchers survey family members on how many hours per week they spend doing various tasks or ask them to keep a diary of what they do every 30 minutes over an entire day over a period of a week. - Time use studies.

Time use studies are studies on the way people spend their time which is what the researchers here hope to find out.