What 3 aspects are ESSENTIAL (not just good or really good) for EVERY experiment

Question

What 3 aspects are ESSENTIAL (not just good or really good) for EVERY experiment? a. Double blinding, randomization, placebos b. Replication, randomization, control c. Treatments, cause and effect, subjects d Control groups, randomization, blocking A member of the City Council has proposed a resolution opposing construction of a new state prison there. The council members decide they want to assess public opinion before they vote on this resolution. Below are some of the methods that are proposed to sample local residents to determine the level of public support for the resolution. Match each with one of the listed sampling techniques. 1 cluster 2 convenience 3 multistage 4 simple (SRS) 5 stratified 6 systematic 7 voluntary response ____ Place an announcement in the newspaper asking people to call their council representatives to register their opinions. Council members will tally the calls they receive. ____ Have each council member survey 50 friends, neighbors, or co-workers. ____ Have the Board of Elections assign each voter a number, then select 400 of them using a random number table. ____ Randomly pick 50 voters from each election district. If you flip a fair coin and get heads 5 times in a row, what is the chance of getting tails on the next flip? A. Greater than 50% B. 50% C. Less than 50% The jukebox from hell contains only three songs: Friday, (Simply Having) A Wonderful Christmastime, and Call Me Maybe. If the probability that Friday is playing is 1/6 and the probability that (Simply Having) A Wonderful Christmastime is playing is 1/3, what is the probability that Call Me Maybe is playing? a. 1/6 b. 1/3 c. 1/2 d. If you pick d, you will be wrong.

Explanation / Answer

28) B option

Control

Suppose a farmer wishes to evaluate a new fertilizer. She uses the new fertilizer on one field of crops (A), while using her current fertilizer on another field of crops (B). The irrigation system on field A has recently been repaired and provides adequate water to all of the crops, while the system on field B will not be repaired until next season. She concludes that the new fertilizer is far superior.

The problem with this experiment is that the farmer has neglected to control for the effect of the differences in irrigation. This leads to experimental bias, the favoring of certain outcomes over others. To avoid this bias, the farmer should have tested the new fertilizer in identical conditions to the control group, which did not receive the treatment. Without controlling for outside variables, the farmer cannot conclude that it was the effect of the fertilizer, and not the irrigation system, that produced a better yield of crops.

Randomization

Because it is generally extremely difficult for experimenters to eliminate bias using only their expert judgment, the use of randomization in experiments is common practice. In a randomized experimental design, objects or individuals are randomly assigned (by chance) to an experimental group.

Replication

Although randomization helps to insure that treatment groups are as similar as possible, the results of a single experiment, applied to a small number of objects or subjects, should not be accepted without question. Randomly selecting two individuals from a group of four and applying a treatment with "great success" generally will not impress the public or convince anyone of the effectiveness of the treatment. To improve the significance of an experimental result, replication, the repetition of an experiment on a large group of subjects, is required.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.