Miguel is studying the effect of positive reinforcement for his psychology class
ID: 3259063 • Letter: M
Question
Miguel is studying the effect of positive reinforcement for his psychology class. He assigns 16 pigeons to two different positive reinforcement schedules. After training the pigeons, he measures the number of correct responses by each in 10 trials. Using a two-tailed test and a = 05 use the data below to determine whether or not there is a difference between the two schedules. a. What type of t-test should she use? b. What are the degrees of freedom? c. What is the appropriate t_ ? d. What are X bar_1 and X bar_2 e. Calculate the standard error of the difference. f. Conduct the appropriate t-test and determine f_ g. What do you conclude? h. If appropriate, calculate the effect size using Cohen's d.Explanation / Answer
a) t-test -2-sample has to be used
b) df = n1 +n2 -2 = 8+8-2 = 14
c) t-critical = 2.144
d) Xbar1 = 6.75 ,X2bar = 5
e) standard error = sp/sqrt(1/n1 +1/n2) = 1.39285/(sqrt(2/8) = 2.7857
f) tobs = 2.9656
g) since tobs is more than t-critical
we reject the null hypothesis and conclude that there is significant difference between two
h) d = Md/Sp = 1.75 /1.39285 = 1.25641669957
t-Test: Two-Sample Assuming Equal Variances Variable 1 Variable 2 Mean 6.75 5 Variance 1.071428571 1.714285714 Observations 8 8 Pooled Variance 1.392857143 Hypothesized Mean Difference 0 df 14 t Stat 2.96561491 P(T<=t) one-tail 0.005112431 t Critical one-tail 1.761310136 P(T<=t) two-tail 0.010224863 t Critical two-tail 2.144786688