QUESTION: During the investigation, Heating Ice Water, the directions stated that you were to bring the water to a boil and allow it to continue to boil for an additional 2 minutes. During that time the temperature would be recorded. Looking at the data, the water started to boil at the 9 minute mark. The temperature recorded was about 100.0 C. While letting the water boil for the additional 2 minutes, the temperature remained about 100.0 C (99.9 C). During that time we continued to add heat, but the temperature remained constant. Why did the temperature never go above 100.0 C? Remember to include information about the four bullet points above in your response.

what are the two models

explanation:

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.