Test 3.3 Flashcards

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1
Q

An experimental design in which the subjects in the experimental and control groups are related in some way

A

correlated-groups design

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2
Q

When the subjects in each condition are different, they are ______ designs.

A

between subjects

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3
Q

There are two types of correlated-groups designs, they are:

A

within-subjects designs and matched-subjects designs

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4
Q

A type of correlated-groups design in which the same subjects are used in each condition

A

within-subjects design

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5
Q

Within-subject designs are often referred to as ______ because we are repeatedly taking measures on the same individuals.

A

repeated-measures designs

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6
Q

In within-subject designs, a random sample of participants is selected, but random assignment is not relevant or necessary because ______.

A

all subjects serve in all conditions

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7
Q

Within subject designs typically require ____ subjects and ___ time than between subject designs.

A

less

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8
Q

Within-subject designs increase _______.

A

statistical power, because individual differences between those conditions are minimized, which in turn reduces variability and increases the chances of achieving statistical significance. It provides a purer measure of the true effects of the IV.

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9
Q

________ designs decreases variability due to individual differences.

A

within-subjects, because the same people are in both conditions, whereas in between-subjects, some of the differences seen could be because of the differences between groups instead of due to the IV.

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10
Q

_____ are a problem for within-subjects designs in which the order of the conditions has an effect on the dependent variable. (Because all participants are measured at least twice).

A

order effects (testing effects)

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11
Q

_____ is a mechanism for controlling order effects either by including all orders of treatment presentation by randomly determining the order for each subject.

A

couterbalancing

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12
Q

_______ involves systematically varying the order of the conditions for subjects in a within-subjects design.

A

counterbalancing

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13
Q

A design with 3 conditions has ______ possible orders .

A

3! = 3x2x1 = 6

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14
Q

A design with 4 conditions has ____ possible orders.

A
4! = 4x3x2x1 = 24
5! = 5x4x3x2x1 = 120
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15
Q

________ is using all of the orderings of conditions

A

complete counterbalancing

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16
Q

One ________ alternative is to randomize the order of presentation of the conditions for each subject. Another is to randomly select the number of orders that matches the number of subjects.

A

partial counterbalancing

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17
Q

A more formal way to use partial counterbalancing is to construct a _______.

A

Latin square

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18
Q

A counterbalancing technique to control for order effects without using all possible orders.

A

latin square

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19
Q

A latin square for a design with four conditions uses _____ orders rather than the 24 orders used in the complete counterbalancing of a design with four conditions.

A

4

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20
Q

A criterion that must be met when constructing a Latin square is that each condition should be presented at each order.
True or False

A

True
For example, for a study with four conditions, each condition should appear once in each ordinal position. In addition, each condition should precede and follow every other condition once.

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21
Q

A type of testing effect often present in within-subjects designs in which subjects “carry” something with them from one condition to another.

A

carryover effects

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22
Q

A type of correlated-groups design in which subjects are matched between condition on variable(s) that the researcher believes is (are) relevant to the study.

A

matched-subject design

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23
Q

_______ share certain characteristics with between and within-subject designs.

A

matched-subject designs

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24
Q

In ________, as in between-subjects design, different participants are used in each condition. However, for each subject in one condition, there is a subject in the other condition who matches him or her on some relevant variable or variables.

A

matched-subject designs

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25
Q

Why would we use matched-subject designs over within-subjects?

A

carryover effects
(drug research, for example.. the subjects cannot take both the drug and placebo) It ensures equivalency when the within-subject design cannot be used.

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26
Q

Which design?

Different subjects are randomly assigned to each condition

A

between subjects (description)

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27
Q

which design?

More participants are needed. More time consuming. Groups may not be equivalent.

A

between subjects (weakness)

28
Q

Which design?

The same subjects are used in all conditions.

A

within-subjects (description)

29
Q

Which design?

Subjects are randomly assigned to each condition after they are matched on relevant variables.

A

matched-subject design (description)

30
Q

Which design?

Fewer participants are needed. Less time consuming. Equivalency of groups is ensured. More powerful statistically.

A

within-subjects (strengths)

31
Q

Which design?

Testing effects are minimized. Demand characteristics are minimized.

A

between subject design (strengths)

32
Q

Which design?

Probability of testing effects is high. Probability of demand characteristics is high.

A

within subjects design (weakness)

33
Q

Which design?
Testing effects are minimized, Demand characteristics are minimized. Groups are more fairly equivalent. More powerful statistically.

A

Matched-subject (strengths)

34
Q

Which design?

Matching is very difficult. More participants are needed.

A

Matched-subject (strengths)

35
Q

If a researcher wants to conduct a study with four conditions and 15 subjects in each condition, how many subjects will be needed for a between-subjects design? for within-subjects?

A

The researcher will need 60 subjects for a between-subjects design and 15 subjects for a within-subjects design.

36
Q

A parametric inferential test used to compare the means of two related (within– or matched-subjects) samples.

A

correlated-groups t test

37
Q

A correlated-groups t test is used for what design(s)?

A

within-subjects or matched-subjects

38
Q

A correlated-groups t test indicates whether there is a difference in the sample means and whether this difference is greater than would be expected based on chance.
True or False

A

True

39
Q

In a correlated-groups design, the sample would include ____ scores for each person.

A

two scores for each person, instead of just one.

40
Q

To conduct the t test for correlated groups, what must be done to the scores?

A

we must convert the two scores for each person into one score, by computing a difference score for each person by subtracting one score from the other for that person.

41
Q

The calculations for the correlated-groups t test involve transforming the two sets of scores into one set by determining __________.

A

difference scores.

42
Q

Scores representing the difference between subject’s performance in one condition and their performance in a second condition.

A

difference scores

43
Q

t = _ _
D - 0 / SD

D = each difference score
_
D = mean of the difference scores

N = the sample size
_
S D = standard error of the difference scores.

∑ = total

A

calculations for the correlated groups t test

44
Q

_______ is the standard deviation of the sampling distribution of mean differences between dependent samples in a two-group experiment.

A

Standard error of the difference scores

45
Q

For the correlated groups t test. the equation to fin the degrees of freedom is:

A

N-1

46
Q

If t obt = 3.85, a=.05, there are 8 participants, what will our decision be on the null hypothesis?

A
df = 7, t cv = 1.895 
t(7) = 3.85, p
47
Q

As with the independent-groups t test, we should also compute _________ for the correlated-groups t test.

A

cohen’s d

48
Q

The proportion of variance in the dependent variable that is accounted for by the manipulation of the IV. It indicated how large a role the conditions of the IV play in determining scores on the DV.

A

Cohen’s d

49
Q

Cohen’s d for a correlated-groups design is interpreted in the same manner as d for an independent-groups design. That is, small effects size is ____, medium is _______, and large is ______.

A

small is .20, medium is .50, and large is .80

50
Q

What are the assumptions for the correlated-groups t-test? (hint: they are the same for the independent-groups, only the observations are not independent they are correlated).

A
  • data are interval-ratio scale
  • the underlying distributions are normal
  • the observations are dependent or related
  • if we could compute the true variance of the population represented by each sample, the variances in each population would be the same, which is called homogeneity of variance.
51
Q

The correlated groups t-test is a parametric test for a two-group ________ or ________ design.

A

within-subjects design or matched-subjects design

52
Q

What does the correlated groups t-test do?

A

Analyzes whether each individual performed in a similar or different manner across conditions.

53
Q

What are difference scores with respect to the correlated-groups t test and how are difference scores calculated?

A

Difference scores represent the difference in performance for each subjects between the two treatment conditions in the study. Thus, to calculate the difference scores, we subtract each subject’s score in one condition from their score in the second condition - consistently subtracting scores in condition A from condition B for each subject (or vise versa).

54
Q

When calculating the correlated-groups t test, why does the numerator for the equation involve subtracting zero from the mean of the difference scores?

A

We subtract 0 from the mean of the difference scores in the numerator for the correlated-groups t test because the 0 represents µ (what we expect the mean of the difference scores to be if the independent variable had no effect). in other words, if the independent variable did not affect subjects’ performance, then we would expect the subjects to receive the same score in each condition. This would lead to difference scores of zero for each subject, and the mean difference score across all subjects would be zero. Thus, if in an experimental study the IV really had no effect, the numerator for the t test would be (D-µ), and the t score would be zero. However, if the IV had an effect, then the numerator will be greater than zero because we would have a number larger than zero (D - the mean of the difference scores) minus 0 (µ - what we expect the difference scores to be when the IV has no effect).

55
Q

If the order of conditions affects the results in a within-subjects design, there are ______.

A

order effects

56
Q

A procedure used to combat order effect is known as_ .

A

counterbalancing

57
Q

A special type of counterbalancing technique for designs with many possible orderings is known as a _____

A

Latin-square

58
Q

A ____ is a parametric inferential test used to compare the means of two related samples.

A

correlatd-groups t test

59
Q

When using a correlated groups t-test, we calculate ___, scores representing the difference between subjects’ performance in one condition and their performance in a second condition.

A

difference

60
Q

The standard deviation of the sampling distribution of mean differences between dependent samples in a two-group experiment is the _____

A

standard error of the difference score

61
Q

Within-subjects design is to between-subjects design as ______ is to ______.

A

using the same subjects in each group; using different subjects in each group

62
Q

Which of the following represent correlated-groups design?

a. matched-subject design
b. between-subjects design
c. within-subjects designs
d. all of the above.

A

a. matched-subject design
and
c. within-subjects designs

63
Q

A matched-subject design uses:

a. the same subjects in each condition
b. different subjects in each condition
c. some of the same subjects and some different subjects in each condition
d. different subjects in each condition, but they’ve been matched on a variable of importance to the study

A

d. different subjects in each condition, but they’ve been matched on a variable of importance to the study

64
Q

If a correlated-groups t test and an independent groups t test both have df= 10, which experiment used fewer subjects?

a. both used the same number of subjects (n=10)
b. both used the same number of participants (n=11)
c. the correlated-groups t test
d. the independent-groups t test

A

c the correlated-groups t test

65
Q

If researchers reported that, for a within-subjects design, t(15) = 2.57, p

A

a total of 16 people participated in the study.

66
Q

Ha:µ1-µ2>0 is the ________ hypothesis for a _______- groups t test.

a. null;independent
b. alternative;independent
c. null; correlated
d. alternative;correlated

A

d. alternative; correlated