Exam 5: Sampling and Probability

A weight-loss guru is offering free exercise training and diet plans for people who want to participate in her program.She finds that 85 percent of the participants who signed up lost an average of 30 pounds in just six months.She then promotes her program as the most effective plan available and promises each participant a weight loss of 20 pounds or more.Is her plan really as effective as she says?

A researcher interested in the concept of preparedness sets up a booth at a local mall.Her idea is to compare men and women in terms of what they carry on their person, and to evaluate what types of events or issues they are prepared to handle based on what they are carrying with them.She hangs a sign on her booth that reads, "Research study underway; stop here to participate." Everyone who willingly participates in her study is part of a:

The extent to which research findings from one sample or context can be applied to other samples or contexts is called:

What is the correct formula for calculating a probability?

External validity is _____ by the use of volunteer samples.

Studies in which the researcher failed to reject the null hypothesis are more likely to be published than studies that rejected the null hypothesis.

A study that does not generalize beyond the specific context and people of the experiment being conducted lacks _____ validity.

Many people have been interested in the effects of pet ownership on overall health.Surprisingly enough, the results have been somewhat inconclusive to date.A major investigation of the issue might compare pet owners to people without pets over a 5- to 10-year period.Which group is the experimental group?

Failing to reject the null hypothesis is the same as accepting the null hypothesis.

Probability is calculated by dividing the number of successes by the number of trials.

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

A researcher who fails to reject the null hypothesis when the null hypothesis is in fact false has:

Marco insists that women are poorer drivers than men.To back up his claim he describes two incidents: one in which his girlfriend sideswiped a car and a second in which his mother failed to react in time to avoid hitting a squirrel on the highway.Marco's attention to this positive evidence for his belief reflects:

As a woman, Jenny has noticed that males always use the middle armrests on airplanes.While those armrests are shared by two seats, she never seems to get to use them if she is in a center seat between two males.Jenny can remember several cases where this has happened to her.Her selective memory for these cases is an example of:

A false-positive pregnancy test is an example of a Type I error.

A trial refers to each time a procedure is:

Students who post responses on ratemyprofessor.com are what type of sample?

In the late 1990s, several studies claimed there was a direct link between growing rates of autism and the presence of low doses of mercury used to preserve infant immunizations.In 2000, the FDA replaced all preservatives in infant inoculations with a recently developed non-mercury-based preservative that was cheaper and more efficient.Some theories stated that the government was engaged in a cover-up because it knew that mercury-based immunizations given during infancy increased the chances of young children developing autism.What is this conclusion most likely an example of?

A researcher is interested in comparing reaction time differences between men and women.He obtains a sample of 45 students from a psychology student research database.Participants take part in the study, the data are later analyzed, and the researcher concludes that women have faster reaction times compared to men.What is a potential limitation of the study's conclusion?

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.Any difference found between these groups would be of interest to the researcher, as well as to the popular media.Which statement is an appropriate research hypothesis for this research?