To Select a Descriptive Statistic Frequency Distribution Table

To Select a Descriptive Statistic Frequency Distribution Table Present entire distribution Table al in Nominal or Ord Table or graph? Grap h Scale of measurement? Histogram Interval or Ratio l rva Inte atio or R Central tendency Bar Graph Skewed, openended, or undetermined scores? or Polygon No Mean Yes Ordinal Median Nomina l Mode Summarize entire distribution Standard Deviation Mean Variability Median What measure of central tendency? Mo No de Location relative to the mean Nominal scale? Yes Range or Semi-interquartile Interquartile Range range or Range None z-Score Describe individual score Standing relative to other scores Percentile Ranks

To Select a Statistic to Measure the Relationship Between Two Variables ar Line Both variables measured on interval or ratio scale? ne No No Data consist of 2 scores for each individual How many dichotomous variables? Only o ne Two Yes Measure linear or monotonic relationship? Both variables measured on ordinal scales? Mon oton Yes No ic Pearson Correlation Spearman Correlation If possible, rank order both variables and use Spearman. Otherwise, convert to frequency data and use chisquare test for independence. Point-Biserial Correlation Phi-Coefficient Data consist of frequency values for each category Chi-Square Test for Independence

To Select a Parametric Statistic to Evaluate Group Differences Yes z-score Test Is σ known? No e On How many scores for each subject? Two More t han tw Single-Sample t-Test Related-Samples t. Test o On e Repeated-Measures ANOVA Two How many separate samples? Matched or independent samples? Related-Samples t. Test Matched Independent. Measures t-Test et or M wo nt ha Repeated-Measures ANOVA Matched or independent samples? Matched Indep ende nt How many independent variables? One Two Single-Factor ANOVA Two-Factor ANOVA

To Select a Nonparametric Statistic to Evaluate Group Differences r more Two o How many categories of measurement? One Only t wo How many scores for each subject? No On e o M How many separate samples? Matched or independent samples? Can difference scores be ranked? hed atc Ind e Binomial Test Sign Test Tw Two Chi-Square Goodness of Fit Wilcoxon Test Yes Mann-Whitney Yes pen den t No Can scores be ranked with few tied values? Chi-Square Test for Independence Mo re Median Test wo nt tha No Chi-Square Test for Independence e et Discr Independent samples only Are scores discrete or continuous? Continuo us Median Test