Statistics

• Two-Way ANOVA involves 2 independent variables and 1 dependent variable.
• Unequal Variance means that groups are unequal.
• One-Way ANOVA is a comparison of differences involving 3 or more independent variables and 1 dependent variable.
• T-Test (Independent) is a comparison or determining differences.
• Age-Related Norms are certain tests that have different normative groups for particular age groups.
• Norm-Referenced Tests compare each person with the norm.
• T-Test (Dependent)/Paired Test is used for two groups, one of which is nominal (either matched or repeated measures) and the other has continuous scales.
• Psychological Assessment Statistics involve two different groups/independent samples and interval/ratio scales (continuous variables).
• Criterion-Referenced Tests describe specific types of skills, tasks, or knowledge that the test taker can demonstrate.
• Norms refer to the performances by defined groups on a particular tests.
• Principle of Least Squares is a standard in regression analysis.
• Equal Variance means that 2 groups are equal.
• Critical Value is the value that rejects the null and accepts the alternative if obtained.
• P-Value (Probability Value) is the value that rejects the null and accepts the alternative if p-value is less than the alpha level.
• Slope in regression analysis determines how much the Y variable changes when X is increased by 1 point.
• Standard Error of Estimate is the standard deviation of the residuals in regression analysis.
• Tracking is the tendency to stay at about the same level relative to one’s peers.
• Statistical method that uses a sample data to evaluate a hypothesis about a population.
• Outlier is an extremely atypical point located at a relatively long distance from the rest of the coordinate points in a scatterplot.
• The Pr is the probability that the null hypothesis is true.
• Rank Biserial Correlation is used when there are nominal and ordinal (rating) variables.
• Correlation Coefficient is a number that provides us with an index of the strength of the relationship between two things.
• Predict the values of a dependent or response variable based on values of at least one independent or explanatory variable.
• Directional Hypothesis Test or One-Tailed Test states that the statistic hypotheses specify either an increase or a decrease in the population mean.
• T-Test is used to test hypotheses about an unknown population mean and variance.
• Alternative Hypothesis states there is a change, difference, or relationships.
• Pearson r/Pearson Correlation Coefficient/Pearson Product-Moment Coefficient of Correlation is used when two variables being correlated are continuous and linear.
• Kendall’s Coefficient is used when there are 3 or more rank/ordinals (ratings).
• The alpha level for a hypothesis test is the probability that the test will lead to a Type I error.
• Spearman Rho/Rank-Order Correlation Coefficient/Rank-Difference Correlation Coefficient is frequently used if the sample size is small and when both sets of measurement are in ordinal.
• Critical Region is composed of extreme values that are very unlikely to be obtained if the null hypothesis is true.
• Phi or Fourfold Coefficient is used when there are nominal variables.
• Residual is the difference between an observed value of the response variable and the value of the response variable predicted from the regression line.
• Regression Analysis is used for prediction.
• If sample data fall in the critical region, the null hypothesis is rejected.
• Null Hypothesis states there is no change, no difference, or no relationship.
• Tetrachoric Correlation is used when both variables are measured as nominal (e.g., Passed or Not Passed, rather than grades itself).
• Correlation is an expression of the degree and direction of correspondence between two things.
• Alpha Level or Level of Significance is used to define concept of “very unlikely” in a hypothesis test.
• Psychological Assessment involves the use of statistics, scales of measurement, and error.