Final answer:
The researcher should implement a multiple baseline design when initial observations show a trend towards improved behavior. They must account for other variables that may affect the results. A scientist with a new idea should formulate a hypothesis and experimentally test it.
Step-by-step explanation:
When the observations in the initial baseline phase show a trend in the direction of improved behavior, the researcher should implement a multiple baseline design. This is because the trend indicates that there may be other variables at play influencing the behavior, which can confound the results of the intervention. A multiple baseline design can help in identifying the effects of the intervention by staggering the start times of the intervention across different conditions or subjects, thereby providing a more robust experimental control.
A scientist who develops a new idea based on their observations of nature should formulate a hypothesis and design an experiment to test this hypothesis. This is the next step in the scientific method, and it allows the scientist to systematically investigate their idea and gather data to support or refute it.