Study Guide to Accompany Salkind and Frey′s Statistics for People Who

Book Preface

LEARNING OBJECTIVES

– Understand the purpose and scope of statistics.
– Review (briefly) the history of statistics.
– Get an introduction to descriptive and inferential statistics. lz Review the benefits of taking a statistics course.
– Learn how to use and apply this book.

SUMMARY/KEY POINTS

Introduction to Part I

– Researchers in a very wide variety of fields use statistics to make sense of the large sets of data they collect in studying a great number of interesting problems.
– Michelle Lampl, a pediatrician and anthropologist, has studied the growth of infants,
finding that some infants can grow as much as 1 inch overnight.
– Sue Kemper, a professor of psychology, has studied the health of nuns, finding that the
complexity of the nuns’ writing during their early 20s is related to risk for Alzheimer’s disease as many as 70 years later.
– Aletha Huston, a researcher and teacher, has found that children who watch educa-tional programs on television do better in school than those who don’t.
– Statistics can be defined as “the science of organizing and analyzing information,” making
that information easier to understand.
– Statistics are used to make sense of often large and unwieldy sets of data.
– Statistics can be used in any field to answer a very wide variety of research questions and

A Brief History of Statistics

– Far back in human history, collecting information became an important skill.
– Once numbers became part of human language, they began to be attached to outcomes.
In the 17th century, the first set of data relating to populations of people was collected.
– Once sets of data began to be collected, scientists needed to develop specific tools to
answer specific questions. This led to the development of statistics.
– In the early 20th century, the simplest test for examining the differences between the
averages of two groups was developed.
– The development of powerful and relatively inexpensive computers has revolutionized the field of statistics. While individuals can now conduct complex and computationally intensive statistical analyses with their own computers, they can potentially run analyses incorrectly or arrive at incorrect conclusions regarding their results.

– Today, researchers from a wide variety of fields use basically the same techniques, or statistical tests, to answer very different questions. This means that learning statistics enables you to conduct quantitative research in almost any field.

Statistics: What It Is (and Isn’t)

– Statistics describes a set of tools and techniques that is used for describing, organizing,
and interpreting information or data. It helps us understand the world around us.
– Descriptive statistics are used to organize and describe the characteristics of a collection
of data. The collection is sometimes called a data set or just data.
– Inferential statistics are often (but not always) carried out after descriptive statistics. They are used to make inferences from a smaller group of data to a larger one. An example is using results from one kindergarten classroom to infer, or generalize, about a population of a whole kindergarten grade.

– A sample is a portion or subset of a larger population. Data from samples may be used for
description only, or to generalize something about the larger population.
– A population is a full set from which a sample is taken: all the possible cases of interest.

– Data from a sample can be used to infer properties of a whole population.