Chapter 1Prepared by Samantha Gaies, M.A.1 Chapter 1: Introduction Why Study Statistics? –To understand published empirical research –To understand the process of drawing inferences from samples to populations –To conduct and report your own research Populations vs. Samples –Populations are summarized by parameters –Samples are summarized by statistics –Random samples are preferred to samples of convenience

Chapter 1Prepared by Samantha Gaies, M.A.2 Scales of Measurement –Nominal (categorical, qualitative) e.g.) Breeds of dogs or cats; political parties; religious affiliations –Ordinal e.g.) Class rankings; rating a teacher as excellent, good, fair, or poor –Interval e.g.) Temperature in degrees on the Fahrenheit or Celsius scales –Ratio e.g.) Weight measured in pounds; height measured in inches Independent Variables (IVs) and Dependent Variables (DVs) –True IVs involve conditions that are created by the researcher. –DVs are measured by the researcher and are often expected to be affected by an IV.

Chapter 1Prepared by Samantha Gaies, M.A. 3 Summation Notation e.g.) X: 3, 2, 5Y: 4, 1, 6 Rule 1: Rule 2:

Chapter 1Prepared by Samantha Gaies, M.A.4 Rule 3: Rule 4: Rule 5: If N = 3 and k = 8, then:

Chapter 1Prepared by Samantha Gaies, M.A.5 Rule 6:, therefore: Rule 7: so, Rule 8: so,