Sample Items for the Final

Psychology 303, Fall 2002

(20)  For the following examples, please list the IV(s) and the DV(s), and select the best description of the design employed.  All examples are drawn from journal article abstracts.  In some cases the abstract has been altered slightly to simplify or clarify.

A visual preference procedure was used to examine 18-, 6-, and 4-month-old infants’ sensitivity to phrase structure in music.  Infants listened to sections of Mozart minuets that were divided into segments that did and that did not correspond to the phrase structure of the music.  Infants in all age groups listened significantly longer to the segments that corresponded to the phrase structure of the music.  There was no difference among the age groups, suggesting that protracted musical experience may not be necessary to perceive phrase structure in music.  Krumhansl & Jusczyk (1990) Psychological Science, 1, 70-73.


 DESIGN (Selected from below):  ________

“Work expands so as to fill the time available for its completion,”  Parkinson’s law, is an explanation classic that has survived without an artifact-free demonstration at the individual level.  To evaluate Pakinson’s law, undergraduate subjects expected to judge four sets of photos of faces with reference to a subjective criteria.  The experimental subjects, who were told that the fourth set was canceled before they began work on the third set, dallied on the third set; that is, as compared with control, they prolonged work.  The cancellation-dalliance effect was re-obtained to two exact replications.  The generalizability of the effect and explanations for it are discussed.      Brannon, Hershberger, & Brock (1999).  Psychonomic Bulletin and Review, 6, 148-156.
 DESIGN (Selected from below):  ________
 STATISTIC (Selected from below):  ________

a.  Basic two group between-subjects experiment
b.  Basic within-subjects with two levels
c.  Basic status variable with two groups
d.  One multiple level between-subjects IV
e.  One multiple level within-subjects IV
f.  One multiple level status variable
g.  factorial design: 2 between-subjects variables
h.  factorial design: 2 status variables
i.  factorial design: 2 within-subjects variables
j.  factorial design: 1 status; 1 between
k.  factorial design: 1 between; 1 within
l.  factorial design: 1 status; 1 within

(10)  For the following source table, please fill in the missing information.

 A 3x3 between-subjects ANOVA on number of words recalled revealed a main effect of number of rehearsals, F (2, 81) = 15.02, p < .001, MSE = 15.20, an effect of learning condition, F (2, 81) = 6.65, p < .001, MSE = 15.20, and no interaction, F (4, 81) = 1.67, p > .05, MSE = 15.20.

Source                                 SS         Df                   MS                   F-ratio               Probability
    Learning Condition
    R x L

(10)  For the following one-way within-subjects source table do two things. First, please fill in the missing information.  Second, calculate the F-ratio and find the associated probability if the data had been analyzed using a one-way between-subjects ANOVA (do this in the space below the source table).

Source                                 SS         Df                   MS                   F-ratio               Probability
    Social Setting                                                       4.45
Error                                 24.99         38
Subjects                                              19
     Total                             334.67

If the same data was analyzed using a one-way between-subjects ANOVA used:



(10)  Describe the post-hoc comparisons needed in a 2x3 factorial design when a two-way between-subjects ANOVA finds no main effect for the first factor, a main effect for the second, and an interaction.  Explain why these comparisons are needed.

(20) For the following set of means, please draw a graph of the means.  In drawing your graph, please label the x and y-axes carefully.  Then predict whether a 2 x 2 between-subjects ANOVA would find main effects (for each factor) and whether the interaction would be significant.  If you suspect that the ANOVA would give you a main effect that would be an artifact of an interaction, please state that as well.  (Keep in mind that your experiment has reasonable power -- i.e., enough subjects -- 20 per cell, and moderate error variance to discover effects if they are meaningful.)

                                                         Post-event information
Delay interval                               Misleading             Consistent
5 m                                         3.85 (SD = 1.89)         7.75 (SD = 1.94)
10 m                                       4.13 (SD = 1.43)         4.45 (SD = 1.61)

DV:  Confidence in the correct answer on a scale from 1 (low confidence) to 9 (high confidence)

 (10)  Define an artifact of the interaction.  Comment on how this will impact the interpretation of an ANOVA finding of a main effect of an independent variable.

 (20)  This is a 2 page question.  What do you know about this study based on the following results paragraphs?  Be sure to mention basic research question, IV and levels, DV(s), design, statistics employed, number of subjects, and findings. Answer these on the next page!

Performance on the first main test questionnaire is summarized in Table 1.  This gives the numbers of subjects and means scores out of 16 for each group (UGM1 – first year math student who received training in reasoning; UGM2 – second year math students who received training the previous year; BSM – boys studying math in a high school; PGMT – graduate students learning to teach math; UGA – undergraduates not taking math classes), each form of the questionnaire (W – words only; ID – inessential pictures with the words; ED – Essential pictures), and for each of the 5 x 3 cells.  It also gives the overall mean score.
 Analysis of variance was applied to the 118 individual scores classified by group and form of questionnaire.  This showed a significant difference in performance between the groups (F (4, 111) = 5.10, p < .001).  .  Scheffe’s comparisons showed that the UGM1 group, which received recent explicit training in reasoning, though not in problems of this type, performed significantly better than all others in this study.  The mean score for the UGM1 group was 14.2 and for the other groups 11.0.  The mean scores for the W, ID, and ED questionnaires were 11.9, 11.4, and 10.9, respectively.  This difference between questionnaires was not significant (F (2, 111) = 1.03).  Makovits’ findings says nothing about scores on the ID, but suggests that the mean score of the ED should be significantly better than that on the W.  An independent samples t-test on the subjects who took the W and ED forms gave no more than weak support (t (84) = 1.31, p < .1; one-tailed).

Table 1.  Mean (standard deviation) performance scores of the five groups on the first main questionnaire (W, ID, or ED).

                                                       W                      ID                      ED
Group                     N                 n Mean                  n Mean             n Mean                 Group Mean
UGM1                     19             9 14.1 (2.6)             6 14.8 (1.7)      4 13.3 (3.1)         14.2 (2.5)
UGM2                     23            11 11.3 (3.1)            6 11.8 (2.7)      6 10.3 (3.1)         11.2 (3.1)
BSM                        38            19 12.0 (2.6)          10 9.8 (2.1)        9 9.8 (3.0)           10.9 (2.8)
PGMT                     24             11 11.5 (3.2)            6 11.3 (2.8)     7 11.7 (3.9)          11.5 (3.3)
UGA                       14               7 10.1 (2.0)            4 10.0 (2.0)      3 10.7 (2.5)         10.2 (2.1)
Total Number            118                 57                          32                      29
Overall Mean                               11.9 (3.0)              11.4 (2.9)              10.9 (3.4)         11.5 (3.1)

From: Nelson & Hannan (2002).  Applied Cognitive Psychology, 16, 157-170.

Basic Research Question:


Levels of IV(s)



Stats Employed:

Number of Subjects: