Question

In a study of memory development, researchers selected pictures that could be classified into one of five categories (food, clothes, toys, furniture, animals). The pictures were presented in a random order to 8 3-year-olds and 8 4-year-olds, who were asked to memorize the pictures. The researchers used the order in which the pictures were recalled to obtain a clustering score for each child. A score of 1 meant that the pictures were not clustered by category at all during recall; whereas a score of 10 reflected perfect clustering of objects during recall (for example, all foods recalled first, then all animals, then all toys, etc.).

                                 

Using alpha = .05, determine whether or not the children of different age groups differed in terms of clustering in memory.

                                    Clustering Scores

      3 years old                                                    4 years old            

                2                                                                              5

                1                                                                              2

                2                                                                             7

                3                                                                              9

                1                                                                              6

                7                                                                              9

                4                                                                              3

                6                                                                              7

a. Identify the appropriate statistical test.

Independent groups t-test

b. State the null and alternative hypotheses.

c. What is the critical value of the test statistic? What is the decision rule for rejecting the null hypothesis?

CV:         _________________________       Reject H₀ if t _____________________

d. Paste in your SPSS output here. Circle the means, standard error, and observed value of t on the output.

Show your work for t (using formula and plugging in appropriate numbers from output) and eta² here:

t_obs=

eta² =

e. Write out an APA Style conclusion about the research project, using the context of the study in your answer.

Answer 1

NULL HYPOTHESIS H0:

ALTERNATIVE HYPOTHESIS Ha:

Critical value= 2.14

Reject H0 if tobs > t cal

tobs= -2.280

eta squared = 30.250/111.750 =0.2707

Since it is two tailed test then > 2.14 therefore significant hence REJECT H0.

We have sufficient evidence to conclude that the  children of different age groups differed in terms of clustering in memory.