title: Reading a research article part II: parametric and nonparametric statistics.
abstract: Researchers often try to use a randomization technique in an attempt to reduce bias and ensure that treatment and control groups are as similar as possible. This article has provided an overview of how researchers might use parametric and nonparametric statistics when analyzing data and looking for differences between groups. Researchers must consider the types of data and choose the tests that are appropriate for the variable types to draw appropriate conclusions. The next article in this series will address comparison of more than two groups and repeated measures and other design issues.
authors.affiliation: Saint Louis University Cancer Center, Missouri, USA. oliverda@slu.edu
authors.forename: Dana
authors.initials: D
authors.lastname: Oliver
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Mahon
mesh_terms: D017677:Age Distribution; D000465:Algorithms; D000704:Analysis of Variance; D001943:Breast Neoplasms / Q000453:epidemiology / Q000473:pathology; D016009:Chi-Square Distribution; D015986:Confounding Factors, Epidemiologic; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D016011:Normal Distribution; D015399:Nursing Research / Q000379:methods*; D016016:Proportional Hazards Models; D011897:Random Allocation; D015203:Reproducibility of Results; D012107:Research Design; D018401:Sample Size; D015983:Selection Bias; D018709:Statistics, Nonparametric; D016019:Survival Analysis