PSYSTATS chapter 1

A random sample

In which every unit of a particular size has an equal probability of being selected

Statistics is often used to make sense of a large set of data. 

True

Stratified sampling

Can be more representative than simple randomized sampling, and it can be used if the population has a number of distinct groups. It is done by randomly sampling from subgroups in a way that is proportional to their size in the population.

A _______________ is a portion or subset of a larger population. 

sample

The word “data” refers to the information that has been collected from an experiment, a survey, an historical record, etc.

true

When participants who arrive for a research study are put into treatment groups on the basis of chance, ___________

Random assignment has occurred

We want to find the average GPA of a student at our college. Our college has 4,834 students, and you select 300 students at random and ask them about their GPAs. The population is_____________ and the sample is _____________.

4,834 and 300

The newspaper reports that higher rates of drowning and ice cream consumption correspond. Does that mean that eating ice cream can put you at risk of drowning? What might be the reason behind this phenomenon?

In summer both ice cream consumption and swimming increases

With descriptive statistics, we take a sample, or a small subset of a larger set of data. We then use this sample to draw inferences about the population as a whole.

False

The study of statistics involves math and relies upon calculations of numbers. But it also relies heavily on how the numbers are chosen and how the statistics are interpreted.

true

A sample of only those students seated in the front row of class would be an unbiased sample.

False

Using a random sample is to accept some uncertainty about the conclusions.

True

Which type of sampling is the most straight forward?

simple random

Uncertainty regarding conclusions about a population can be eliminated if you

Obtain data from all members of the population

A Biased sample is one that ______

Will likely have certain groups from the population over-represented or under-represented due only to systematic sampling factors