A team of researchers is investigating the question, "Does more knowledge about money management of husbands and wives cause less disagreement between the spouses about money?" They are considering three different research designs:

Design 1:
They will recruit 50 couples from attendees at a martial enrichment workshop on the CSUN campus. At the beginning of the workshop, the couples will complete a scale measuring disagreement about money. Also, data on the couples' age, education, number of children, length of marriage, wives' employment, and other characteristics that theoretically affect disagreement about money will be collected. These couples will receive training in money management techniques at their workshop. Simultaneously, the researchers will recruit a group of 50 attendees at another CSUN conference where no money management training will be offered. They administer the money disagreement scale and the other variables of this group at their conference. From these completed questionnaires, the researchers will choose an equal number of these respondents as they have from the marital enrichment group; these individuals will be matched on several relevant characteristics across the two groups. One month later, both groups of chosen attendees will be mailed an evaluation of their workshop (conference); embedded in the questionnaire will be the same measure of spouses' disagreement about money.

Design 2:

They will randomly select 300 married couples from marriage license applications in 10 cities over the past 5 years. Using a mailed questionnaire, they will measure their money management knowledge and their money disagreement. One the same questionnaire, they will measure other variables such as their age, length of marriage, education, number of children, wives' employment, etc. that need to be controlled.

Design 3:

They will recruit 200 married couples from a University population of married student couples (via flyers, ads in the student newspaper, etc.) and randomly assign these couples to groups. Each couple will be observed in a University marital therapy center under controlled conditions while they try to solve an unsolved problem about money. Couples in one group will be observed in problem solving session during which their extent of money disagreement will be measured observationally. Then, they will view a money management videotape. Then, they will be asked to solve another problem during which observation will be made of their extent of disagreement. A second group will just be observed twice in two problem-solving sessions without viewing the videotape. A third group will view the money management videotape followed by an observational session of problem-solving. A fourth group will only be observed in the second problem-solving session during which their extent of disagreement is observed.

a. Name (completely) the research design used in each of these three studies:

b. Diagram each research design and label tests and treatment precisely: