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.

Making Inferences: Confidence Limits and Statistical Significance

Making inferences: Confidence limits and statistical significance

What's in This Chapter?

  • Calculating the standard error
  • Probability
  • Hypotheses
  • t distribution
  • Degrees of freedom
  • Confidence intervals
  • Using SPSS

Key Terms


alternative hypothesis

confidence interval

confidence limits

degrees of freedom

descriptive statistics



normal distribution

null hypothesis

one-tailed (or directional) hypothesis



standard error

statistically significant

t distribution

two-tailed (or non-directional) hypothesis

type I error

type II error



This chapter is about the way we make inferences and statements of significance. It is also about how much tolerance there is in our results. By ‘tolerance’ we mean the how certain we are about our results. For example, when students take A levels they are given a grade from A to U, but there is bound to be some variation in the way the examinations are marked. It is generally agreed, though rarely reported, that the tolerance ...

  • Loading...
locked icon

Sign in to access this content

Get a 30 day FREE TRIAL

  • Watch videos from a variety of sources bringing classroom topics to life
  • Read modern, diverse business cases
  • Explore hundreds of books and reference titles