Statistics

• Variance measures the spread of numbers in a data set.
• Skewness is the nature and extent in which symmetry is absent.
• Kurtosis refers to the steepness of a distribution, which can be peaked or flat.
• A Normal Curve is depicted as a bell-shaped line, with no skews and is perfectly symmetrical.
• Sampling refers to the process of selecting a representative of a population.
• TYPES OF SAMPLING

  • Stratified
  • Purposive
  • Convenience
• TYPES OF DATA IN PSYCHOLOGICAL RESEARCH

  • Categorical Data (Nominal, Ordinal)
  • Continuous Data (Interval, Ratio)
• Nominal - category

  Ordinal - rank

  Interval - no true zero

  Ratio - true zero
• In correlational statistics, Pearson R is used when one variable is interval/ratio and the other is interval/ratio.
• In correlational statistics, Spearman Rho is used when one variable is ordinal and the other is also ordinal.
• T-test independent is a parametric test where there are two groups that are randomly assigned.
• T-test dependent is a parametric test where there is only one group but two scores will be extracted.
• One way ANOVA is applied to 3 or more groups, while two way ANOVA also has 3 or more groups but with 2 variables. ANCOVA has an added control for the variables involved.