Chapter 7: Single-Factor Designs

Question 1

a single factor design has..

Answer 1

one independent variable and can have 2 or more levels

Question 2

What are the 4 types of single factor designs?

Answer 2

1. independent groups
2. matched groups
3. repeated measures
4. ex post facto

Question 3

What are the questions one must consider when choosing a single-factor design?

Answer 3

1. is the IV between- or within-subjects?
2. is the IV manipulated or a subject variable?
3. if IV is manipulated & BS, will you form equivalent groups by matching or by random assignment?
4. if IV is WS, how many times is it tested per condition?

Question 4

For which single-factor design woud you form equivalent groups using random assignment?

Answer 4

independent groups single-factor design

Question 5

What do we know about a study if it uses an ex post facto single factor design?

Answer 5

The IV is between-subjects and is a subject variable

Question 6

What designs can we use if we have a between-subjects manipulated IV?

Answer 6

matched groups or independent groups designs

Question 7

What design is appropriate for a within-subjects IV?

Answer 7

a repeated measures design

Question 8

What are the assumptions for a t-test?

Answer 8

1. Approximate normal distribution
2. Homogeneity of variance: similar variance of each set of scores being compared

Question 9

when performing a t-test, you can chose between an ____ and a ____ t-test

Answer 9

independent samples, paired (dependent) samples

Question 10

when is an independent samples t-test appropriate?

Answer 10

When the groups being compared are completely independent of each other (i.e., independent groups design and ex post facto design)

Question 11

when is a paired samples t-test appropriate?

Answer 11

if the IV is a within-subjects factor (i.e., in a matched groups design or a repeated-measures design)

Question 12

sWhat is an advantage of single-factor multi-level designs?

Answer 12

they can discover nonlinear effects

Question 13

what becomes possible with within-subjects multilevel designs?

Answer 13

you can counterbalance single-factor, repeated-measures designs in more than one ways

Question 14

When is it more effective to use a graph?

Answer 14

if there are large differences, if nonlinear effects occur, or if the result is an interaction between two factors

Question 15

When is it preferred to use a table?

Answer 15

when data points are so numerous that a graph would be uninterpretable or when the researcher wishes to inform the reader of precise values

Question 16

What is a risk that comes with performng multiple t-tests?

Answer 16

performing a type I error

Question 17

a line graph is appropriate for presenting…

Answer 17

continuous variables

Question 18

a bar graph is appropriate for presenting…

Answer 18

discrete variables

Question 19

A type I error occurs when…

Answer 19

you reject the null hypothesis when it’s true

Question 20

a type II error occurs when…

Answer 20

you accept a null hypothesis that isn’t true

Question 21

What does a one-way ANOVA look for?

Answer 21

an overall significant effect that could exist somewhere between the levels of the independent variable

Question 22

What is a post-hoc analysis used for?

Answer 22

to determine which level of an IV produced the significant effect that was found in the ANOVA

Question 23

What influences the selection of post hoc analysis method?

Answer 23

sample size
how conservative the researcher wishes to be when testing for differences

Question 24

What inferential statistic does a one-way ANOVA produce?

Answer 24

An F-score

Question 25

for which designs can we use a one-way ANOVA for independent groups?

Answer 25

multilevel independent groups design
multilevel ex post facto design

Question 26

for which deisgns can we use a one-way ANOVA for repeated measures?

Answer 26

multilevel matched groups design
multilevel repeated-measures design

Question 27

What is a yoked control group?

Answer 27

when subjects in the experimental group participate for varying amounts of time or are subjected to different types of events in the study, each member of the control group is matched (yoked) to a member of the experimental group so that on average the time spent participating or the types of events encountered are kept constant