Stats Chapter 14
R2 chart for values
.01 small .09 medium .25 large
factorial ANOVA
1 scale variable, 2 nomal IV (multifactorial)
interaction
2+ iV have a effect on the DV in combination that neither IV has on its own
mixed design ANOVA
2IV, IV within groups, 1 variable between groups
how many F statistics are calculated in a two-way between groups ANOVA
3
how many F statistics do 2 way ANOVAs have?
3 - IV - IV - interaction
how many critical values for F statistic
3 bc three F statistics
ANCOVA
ANOVA where a covariate is included so that statisctical findings reflect effects after a scale variable has been statistically removed
MANOVA
ANOVA with more than 1 DV
MANCOVA
ANOVA with multiple DV and covariate
A form of ANOVA in which there is more than one DV is called:
MANCOVA - multiple dependent variables
dfcolumns =
Ncolumns - 1
dfrows =
Nrows - 1
A bar graph displays the mean scores on a test of mental rotation for students majoring in psychology or chemistry who have either high or low spatial abilities. Psychology and chemistry students with low spatial skills scored about 35 percent correct on the mental rotation test, while psychology and chemistry students with high spatial skills scored about 70 percent correct. What can be inferred from these data? Question options: a) There appears to be a main effect of college major only. b) There appears to be a main effect of spatial ability only. c) There appears to be a main effect of mental rotation only. d) There is an interaction between spatial ability and college major.
b
The grand mean in a factorial ANOVA is NOT useful in calculating which of these? Question options: a) total sum of squares b) within groups sum of squares c) sum of squares for factor 2 d) sum of squares for factor 1
b
cell
box that depicts one unique combo of levels of the IV in a factorial design
A cell depicts one unique combination of _____ of the independent variable in a two-way ANOVA. Question options: a) scores b) main effects c) levels d) factors
c
In determining main effects and interactions in a factorial ANOVA, it is helpful to use the _____ in a table of means. Question options: a) line of best fit b) individual scores c) marginal means d) standard error
c
qualitative change
changes direction (interaction)
The Educational Testing Services (ETS) is conducting a study to determine the relation between method of presentation (standard lecture vs. computer presentation) and type of lecture (psychology, English, or statistics) to lecture comprehension. How would we describe the design? Question options: a) 1 X 2 between-groups ANOVA b) one-way ANOVA c) 2 X 3 within-groups ANOVA d) 2 X 3 between-groups ANOVA
d
The grand mean in a factorial ANOVA is NOT useful in calculating which of these? Question options: a) sum of squares for factor 1 b) sum of squares for factor 2 c) within groups sum of squares d) total sum of squares
d
parallel lines =
no interaction
no interaction
parallel lines
For a two way ANOVA, which statistic do we calculate to determine effect size?
r^2
covariate
scale variable that we suspect associates with the IV of interest
ssbetween for interaction
sstotal - (ssbetweenrows +sscolums +sswithin)
T/F: whenever a two-factor design results in a significant interaction, you should be cautious about interpreting the main effects because an interaction can distort, conceal, or exaggerate the main effects of individual factors
true
T/F: if a researcher expects that a new teaching technique will be more effect for high school students than for younger middle school students, then the researcher is predicting an interaction between teaching style and grade in school
true - interaction
A ______ is a hypothesis test that includes two nominal TV and an interval DV, and a _____ is a statistical analysis used with 1 interval DV and at least two nominal IV
two-way ANOVA factorial ANOVA
interaction effects
when the effect of 1 IV on DV changes as a result of a second IV
R2 columns =
SS columns / SStotal - SSrows - SSinteraction
R2 rows =
SS rows / SStotal - SScolumns - SSinteraction
R2 intercation =
SSinteraction / SStotal - SSrows - SScolumns
SSbetween =
SStotal - SS within
One benefit of using a multifactorial ANOVA with two or more factors is that it can detect _____ among the variables, whereas multiple direct comparisons of means cannot. Question options: a) a main effect b) violations of assumptions c) interactions d) significant differences
c
quantitative change
changes magnitube but not direction (no interaction)
In a two-way ANOVA, three _____ statistics are calculated. Question options: a) t b) z c) R2 d) F
d
interaction
intersecting lines
____refers to the means of the rows and the columns in a table that shows the cells of a study with a two-way anova design
marginal mean
marginal means
mean of a row/column in a talbe that shows the cells of a study with a 2 way ANOVA
A researcher for Major League Baseball is interested in visual accuracy of the players. The indicators of visual accuracy are batting average (high vs. low) and a computer "flicker" program that indicates changes in either the central or the noncentral region of a scene. The dependent variable is the time it takes to notice a change during flickers. When the researcher looks at a table of means, the data show that central flicker and high batting average = 40; noncentral flicker and high batting average = 20; central flicker and low batting average = 20; and noncentral flicker and low batting average = 40. Assuming a very powerful statistical test, the researcher should find: Question options: a) no main effects but a significant interaction. b) no main effects and no interaction. c) a main effect for "flicker" type. d) a main effect for batting average.
a
A researcher sets up a study to examine how lecture comprehension of college students is affected by lecture type (history, psychology, statistics, or English), classroom size (large or small), presentation method (blackboard, overhead projector, or computer), and instructor (graduate student, assistant professor, or full professor). How many cells are in this design? Question options: a) 72 b) 24 c) 4 d) 12
a
A student researcher conducts a study that is analyzed using a two-way between-groups ANOVA. Unfortunately, none of the three F statistics were statistically significant. The student is confident that there is something to her research question, and she wonders if she simply didn't collect enough data to detect anything. She computes effect size measures and gets the following values: 0.012 for the first main effect, 0.073 for the second main effect, and 0.0017 for the interaction. If she were to conduct additional research, what would you recommend she pursue? Question options: a) the second main effect because it has a medium effect size b) the first main effect because it has a small effect size c) the interaction because its significance would overshadow both main effects d) the interaction because it has a strong effect size
a
In a _____, the effect of one independent variable reverses based on the _____. Question options: a) qualitative interaction; level of the other independent variable b) hypothesis test; effect size c) quantitative interaction; level of the other independent variable d) quantitative interaction; direction of the difference
a
In a _____, the effect of one independent variable reverses based on the _____. Question options: a) qualitative interaction; level of the other independent variable b) quantitative interaction; direction of the difference c) quantitative interaction; level of the other independent variable d) hypothesis test; effect size
a
Mike wants to test how different levels of verbal ability and math ability influence a measure of reading comprehension and a measure of graph interpretation. He is concerned that IQ may confound the results since it is likely to have an effect, too. What test should he use to account for this third variable? Question options: a) MANCOVA b) MANOVA c) factorial ANOVA d) ANCOVA
a
Which statement BEST describes an interaction in a two-way ANOVA? Question options: a) The two independent variables have a combined effect on the dependent variable that is not present with either independent variable alone. b) The study is a within-subjects design, so all participants receive all levels of each independent variable. c) No variable has a main effect. d) Both independent variables have a main effect.
a
A main effect for a two-way ANOVA is the: Question options: a) research hypothesis of the study. b) influence of one of the independent variables on the dependent variable. c) main experimenter's bias as a confound to the study. d) influence of the dependent variable on one of the independent variables.
b
A researcher wants to examine the effect of drugs and diet on systolic blood pressure. She randomly assigns 20 individuals with high blood pressure to one of four treatments: control (no diet or drugs), diet modification only, drug only, drug and diet modification. What type of design is appropriate for this study? Question options: a) two-way within-groups ANOVA b) two-way between-groups ANOVA c) one-way within-groups ANOVA d) mixed-design ANOVA
b
In a _____, the strength of the effect varies under certain conditions, but not the _____. Question options: a) hypothesis test; effect size b) quantitative interaction; direction c) effect size; z score d) qualitative interaction; F statistic
b
It is helpful to represent the main effects and interactions of a factorial ANOVA graphically in a bar graph because when lines are drawn to connect the bars, they will be _____ if there is a main effect and _____ if there is an interaction. Question options: a) intersecting; flat b) separate but parallel; intersecting c) flat and parallel; intersecting d) separate but parallel; flat
b
In determining main effects and interactions in a factorial ANOVA, it is helpful to use the _____ in a table of means. Question options: a) standard error b) line of best fit c) marginal means d) individual scores
c
Overall, children did not remember more words than adults on a memory test, F (1, 153) = 3.00, p > 0.10, and participants listening to music during the test did not remember more words than those not listening to music, F (1, 153) = 1.98, p > 0.10. However, listening to music significantly aided the children in remembering the words, while it hindered the adults in remembering the words, F (1, 153) = 12.73, p < 0.05. Which effect(s) must be present in this study for these results to be valid? Question options: a) main effect of music b) main effect of age c) interaction of age and music d) main effect of age, main effect of music, and interaction of age and music
c
When determining the critical value or cutoffs for the three effects tested in a two-way between-groups ANOVA, what value is always the same for each effect? Question options: a) degrees of freedom for rows b) degrees of freedom for the interaction c) within-groups degrees of freedom d) degrees of freedom for columns
c
When performing a two-way between-groups ANOVA, effect size is measured using _____, and it is calculated for _____ effects. Question options: a) Cohen's d; three b) R2; two c) R2; three d) Cohen's d; two
c
Which of these is NOT an assumption of a two-way between-groups ANOVA? Question options: a) The underlying population distributions are normal. b) The variability in underlying populations is similar. c) The participants are matched on important characteristics. d) Participants are randomly selected.
c
Which source of variability does not require the grand mean in its calculation? Question options: a) between-groups sum of squares b) total sum of squares c) within-groups sum of squares d) sum of squares for the interaction
c
A researcher is examining the relation between patrol location (more affluent vs. less affluent neighborhoods) and amount of training (5 weeks, 10 weeks, or 15 weeks) to police job performance in a small town. The researcher finds a significant interaction in that the strength of the effect of training varies depending on patrol location; however, the direction of the effect does not change. This type of effect is a: Question options: a) marginal means. b) qualitative interaction. c) main effect. d) quantitative interaction.
d
A researcher sets up a study to examine how lecture comprehension of college students is affected by lecture type (history, psychology, statistics, or English), classroom size (large or small), presentation method (blackboard, overhead projector, or computer), and instructor (graduate student, assistant professor, or full professor). How is the design described? Question options: a) 1 × 1 × 1 × 1 within-groups ANOVA b) 4 × 2 × 3 × 3 within-groups ANOVA c) 4 × 1 between-groups ANOVA d) 4 × 2 × 3 × 3 between-groups ANOVA
d
The Educational Testing Services (ETS) is conducting a study to determine the relation between method of presentation (standard lecture vs. computer presentation) and type of lecture (psychology, English, or statistics) to lecture comprehension. How many cells are in this design? Question options: a) 2 b) 12 c) 5
d
The Educational Testing Services (ETS) is conducting a study to determine the relation between method of presentation (standard lecture vs. computer presentation) and type of lecture (psychology, English, statistics) to lecture comprehension. What kind of ANOVA should ETS use and what are the factors and/or levels? Question options: a) One-way ANOVA: Factor 1 is lecture, with two levels (presentation vs. lecture type). b) Three-way ANOVA: Factor 1 is presentation, with two levels (standard vs. computer), factor 2 is lecture type, with three levels (psychology, English, and statistics), and factor 3 is lecture comprehension. c) Higher-order ANOVA: Factor 1 is standard presentation, factor 2 is computer presentation, factor 3 is psychology lecture, factor 4 is English lecture, and factor 5 is statistics lecture. d) Two-way ANOVA: Factor 1 is presentation, with two levels (standard vs. computer), and factor 2 is lecture type, with three levels (psychology, English, and statistics).
d
What does a two-way ANOVA offer beyond what two separate one-way ANOVAs can tell about the data? Question options: a) information about the primary effect of one variable as the cause of another b) clarification on how one variable is correlated with another variable c) quantitative assessment of main effects d) a chance to see how the effect of one variable can depend on the levels of another variable
d
factor
describe an IV in a study with more than one IV
Which of the following is the correct formula for the interaction effect of a between-subjects factorial design?
dfinteraction = (dfrows) (df columns)
main effects
factorial design when 1 of the IV has an influence on DV
If the AxB interaction is significant, then at least one of the two main effects also must be significant
false
2 way ANOVA
hypothesis test that includes 2 nominal IV< regardless of number of levels and a scale dependent variable
when you get your output from a two-way between-groups ANOVA, which F statistic, if it is significant, should you first interpret?
interaction effects
