Exam 5: Sampling and Probability

A researcher is interested in the eventual divorce rates of people who live together before they get married compared to those who do not cohabitate before marriage.The researcher is particularly interested in the couples who cohabitate to see if that leads to higher divorce rates.In a sense, the couples who cohabitate are serving as the _____ group.

In a study of the effects of humor on memory, Schmidt (1994) had participants read either humorous sentences or non-humorous sentences and then later tested participants' memory for the sentences.Identify the null hypothesis this study.

Without many trials, one cannot determine true probabilities of events.However, over the long run, and numerous trials, the expected relative-frequency probability of events is very clear and predictable.This is known as the:

In a research study, the control group is where experimenters exert more of their efforts, including the experimental manipulation.

Convenience samples are used more often in research than random samples.

Dr.Baker designed an experimental study to assess potential differences between science students and art students on a math reasoning abilities test.Dr.Baker found a mean difference in math performance between science and art students.On average, science students performed higher on the math reasoning test compared to the art students.Dr.Baker's findings support which hypothesis?

A researcher who fails to reject the null hypothesis when in fact it should be rejected commits a Type I error.

Confirmation bias is the tendency to ignore evidence that goes against one's beliefs.

Brent tosses a quarter 4 times and 3 times it comes up heads.The probability of heads is:

A _____ sample is a type of convenience sample.

In a set of clinical trials, a pharmaceutical company wishes to assess the effectiveness of its newly developed drug for depression by comparing its performance to the leading drug currently on the market and to a placebo control.What research technique or techniques would be possible and appropriate?

A tendency to pay attention to evidence that confirms one's a priori belief is called:

In an in-class demonstration of a classic experiment on the effects of smiling on happiness, an instructor had students sitting on the left side of the classroom read a series of cartoons while frowning and had students sitting on the right side of the classroom read the same series of cartoons while smiling.In this example, the instructor failed to:

John flips a coin 20 times and observes 8 heads.Those heads are the successes of his study.

Dan and Rachel decided to start running in the mornings to get a little exercise.Dan asks Rachel if she thinks she will go out for a run today, and she says there is an 80 percent chance that she will.What type of probability is this?

A(n) _____ is a level of the _____ that does not receive a manipulation.

Meredith is a nurse in the obstetrics ward of a hospital.She tells her friend that at her hospital more babies are born when there is a full moon.The hospital's records show no such relationship, however.Meredith's belief is an example of:

In a study of the effects of humor on memory, Schmidt (1994) had participants read either humorous sentences or non-humorous sentences, and then he later tested participants' memory for the sentences.The control group in this experiment was:

Even though it is not always possible to employ random selection, random assignment should be used whenever possible.

In a study of the effects of alcohol, a researcher compares reaction time of people who had 8 drinks against those who had 6 drinks, 4 drinks, 2 drinks, or 0 drinks.How many experimental groups are there in this design?