Chapter 14 Nonparametric Statistics
Chapter 14 Nonparametric Statistics Chi Square (c2) Test for Two Independent Samples
About This Statistic Chi-square (c2) • Independent variable • Two nominally measured levels
• Dependent variable • Categorical variable with two or more levels
Example • Examination performance • Upper (better) or Lower (poorer) half • Response to a given test item (A, B, C, D*)
• N = 100
SPSS Directions AnalyzeDescriptive StatisticsCrosstabs Put Test performance in Row(s) and Response chosen in Column(s). Select Statistics button and select Chi-square. Click Continue and then OK.
Results
Results Response D* is the correct response for this item. Interpretation • ≈50% of the students answered the question correctly • The item did a fair job of discriminating among the good (n = 32) and poor (n = 24) students • The pattern of responses was not significantly different (p < .11) for the two groups.
About This Statistic Chi-square (c2) • Independent variable • Two nominally measured levels
• Dependent variable • Categorical variable with two or more levels
Example • Examination performance • Upper (better) or Lower (poorer) half • Response to a given test item (A, B, C, D*)
• N = 100
SPSS Directions AnalyzeDescriptive StatisticsCrosstabs Put Test performance in Row(s) and Response chosen in Column(s). Select Statistics button and select Chi-square. Click Continue and then OK.
Results
Results Response D* is the correct response for this item. Interpretation • ≈50% of the students answered the question correctly • The item did a fair job of discriminating among the good (n = 32) and poor (n = 24) students • The pattern of responses was not significantly different (p < .11) for the two groups.
