Understanding and Using Statistics in Psychology takes the fear out of psychological statistics to help students understand why statistics are carried out, how to choose the best test, how to carry out the tests, and then perform the analysis in SPSS. Emphasizing the place of statistical analysis in the process of conducting research, from design to report writing, this accessible and straightforward guide takes a non-technical approach, encouraging the reader to understand why a particular test is being used and what the results mean in the context of a psychological study. The focus is on meaning and understanding rather than numerical calculation.

Descriptive Statistics

Descriptive statistics

What's in This Chapter?

• Levels of measurement
• The normal distribution
• Measures of dispersion
• Measures of central tendency
• Graphical representations
• Using SPSS

Key Terms

binary measures

boxplot

categorical measures

ceiling effect

central tendency

continuous measures

descriptive statistics

discrete measures

dispersion

distribution

exploratory data analysis

floor effect

frequencies

histogram

inter-quartile range

interval measures

kurtosis

mean

median

mode

nominal measures

normal distribution

ordinal measures

outliers

range

ratio measures

skew

standard deviation

variable

Introduction

The purpose of descriptive statistical analysis is (you probably won't be surprised to hear) to describe the data that you have. Sometimes people distinguish between descriptive statistics and exploratory data analysis. Exploratory data analysis helps you to understand what is happening in your data, while descriptive statistics help you to explain to other people what is happening in your data. While these two are closely related, they are not quite the same thing, and the best way of looking for something is not necessarily the best way of presenting ...