Chapter 7 Two Sample t-test Independent t-test
Chapter 7 Two Sample t-test
Independent t-test
Hypothesis Testing Research hypothesis of relationship Statistical null hypothesis (Ho) Alternative hypothesis (H1) Obtain data Make decision based on probability
Independent t-test Example Boys/Girls Experimental/Control Active/Sedentary Smoker/Non-smoker
TWO groups ONLY INDEPENDENT
Null Hypothesis (Ho)
Women Men
Lo
Hi Men – Women = 0
Alternative Hypothesis (H1)
Men
Women
Lo
Hi Men – Women ≠ 0
Null Hypothesis DV
Control
Experimental
Anything Happening Here? DV
Control
Experimental
Anything Happening Here? DV
Control
Experimental
Independent t-test Example Are the means statistically significant? Girls’ N = 100
Is there a relationship between gender and curl-up scores?
Boys’ N = 100
M = 48.68
M = 63.37
S = 10.59
S = 10.02
t = 10.07 df = 198 p < .001 Critical t ≈1.96
SPSS Example Boys/Girls and PACER
Independent t-test
Hypothesis Testing Research hypothesis of relationship Statistical null hypothesis (Ho) Alternative hypothesis (H1) Obtain data Make decision based on probability
Independent t-test Example Boys/Girls Experimental/Control Active/Sedentary Smoker/Non-smoker
TWO groups ONLY INDEPENDENT
Null Hypothesis (Ho)
Women Men
Lo
Hi Men – Women = 0
Alternative Hypothesis (H1)
Men
Women
Lo
Hi Men – Women ≠ 0
Null Hypothesis DV
Control
Experimental
Anything Happening Here? DV
Control
Experimental
Anything Happening Here? DV
Control
Experimental
Independent t-test Example Are the means statistically significant? Girls’ N = 100
Is there a relationship between gender and curl-up scores?
Boys’ N = 100
M = 48.68
M = 63.37
S = 10.59
S = 10.02
t = 10.07 df = 198 p < .001 Critical t ≈1.96
SPSS Example Boys/Girls and PACER
