Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Psych 110 (Stats) > Analyzing Data from Independent Groups: Continuous and Ordinal Measures > Flashcards

Analyzing Data from Independent Groups: Continuous and Ordinal Measures Flashcards

1
Q

Most common experimental design in psychological research.

A

Independent group designs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Independent group designs

Used for comparing ______ groups which are independent of one another – meaning there are different people in each group.

A

two or more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Can be used for _____ and ________ designs.

A

true and quasi-experimental

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

people are not assigned to conditions, as they already belong to different groups.

E.g., Males and Females, Normal and Abnormal etc.

A

Quasi-experimental designs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Independent groups designs – three different kinds of ______ can be used.

A

dependent variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Avoids the problems inherent in repeated measures designs;
1.
2.
3.

A

practice effects
sensitization
carry-over effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Disadvantage – more people, difficulty of matching controlled group with ______

A

experimental group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Statistical Tests for Independent Groups Data

A
  1. the independent groups t-test
  2. the mann-whitney test
  3. the chi-square test
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

also called the wilcoxon mann whitney test

A

the mann-whitney test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Use of test depends on data being tested.

A

the chi-square test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

also known as the between subjects t-test or the two samples t-test.

A

the chi-test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Two (or Three) Assumptions about the Data

A
  • Continuous/interval scale
  • Data within each group is normally distributed. We need to make sure that the data are approximately normally distributed within each group.
  • The SD of the two groups are equal.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

there are actually two kinds of t-test, one makes the assumption of ,__________ and one does not.

A

assumption of homogeneity of variance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The one which makes the assumption is _____

A

easier.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Sample size must be above some value, such as 6, for the t-test to be valid

A

dispelling myths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Sample sizes must be balanced, or similar.

A

dispelling myths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

To look at the overall distribution of data to determine whether the data are appropriate for an_______

A

independent samples t-test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

distribution of two (or more) groups can be shown for the same amount of space.

A

Box and whisker plot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

in calculation of the independent groups t-test use _______ instead of histogram

A

box and whisker plot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

We use the ____ – approximately
equal sample sizes.

A

Pooled Variance t-test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

step ____

Calculate the SD of each group.

A

step 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

step ___

Calculate the SD of the Difference.

A

step 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where na means the number of people in group A, and
nb is the number of people in group B.

A

formula for the SD of difference

24
Q

step ___

Calculate the Standard Error of Difference

A

step 3

25
Q

Step ____

Calculate the Confidence Intervals

A

step 4

26
Q

in IG t-test, instead of being interested in
mean scores, we are now interested in the ____
between two means. So we call this d

A

difference

27
Q

The Equal Standard Deviations Assumption also known as ____

A

Homogeneity of Variance.

28
Q

Also known as Homogeneity of Variance.

A

The Equal Standard Deviations Assumption

29
Q

Two versions of the t-test:

A

Pooled Variance t-test
Unpooled Variance t-test

30
Q

Two versions of the t-test: the _____,
which makes this assumption,

A

Pooled Variance t-test

31
Q

Two versions of the t-test: the _____, which does not make this assumption.

A

Unpooled Variance t-test

32
Q

If you have (approximately) equal sample sizes in your
two groups, use the ____

A

pooled variance t-test.

33
Q

If you don not have (approximately) equal sample sizes
in the two groups, use the _____

A

unpooled variance t-test.

34
Q

used to decide if variances (or SDs) are the same. (most common)

A

levene’s test

35
Q

If Levene’s test give gives a statistically significant result, this means variances are different from one another and the _____ should be used. (vice versa)

A

unpooled variance test

36
Q

Problem however is that a ____ does not mean that the variances are the same.

A

non-significant result

37
Q

And the problems with the tests, such as the Levene test, is that they are _____on the sample size.

A

dependent

38
Q

When the sample size is small, it is not very good at detecting differences in the ____. (vice versa)

A

variances

39
Q

It only matters however that the variances are the same when the sample size is _____

A

small.

40
Q

So, when Levene’s test is good at telling us when the variances are different precisely we do not really ____

nd when it is not very good is precisely when we do_____

A

care.

41
Q

_____ does not really matter when the sample sizes are about equal.

A

Homogeneity of variance

42
Q

So, if we have equal (or approximately equal) sample sizes, we can ignore the assumption of Homogeneity of Variance and use the _____

A

Pooled Variances t-test.

43
Q

A modification of the t-test, which does not make the assumption of equal variances.

  • Sometimes known as Welch’s Test which was developed by Welch (1938)
A

unpooled variance test

44
Q

unpooled variance test sometimes known as __ which was developed by welch (1938)

A

Welch’s Test

45
Q

Reasons for having Unequal Sample Sizes

A

Comparison of two naturally occurring groups, and they are different sizes.

It may be difficult or expensive for one of the interventions.

There may be an ethical or recruitment issue.

46
Q

We often describe the difference between two samples by stating the difference between the ____

A

two means.

47
Q

However, often the ____ that is used is not one that actually makes any sense (unless we are very familiar with the _____)

A

scale

48
Q

How do we tell then if the difference is good or bad?

Use a measure of Effect Size, and in the case of the independent groups t-test, an appropriate measure of effect size is called _____

A

Cohen’s d

49
Q

measure of how far apart the means of the two samples are, in SD units.

A

Cohen’s d

50
Q

It does not matter what the range of possible scores is – we are interpreting it in terms of ____

A

SD

51
Q

Cohen’s d is often interpreted according to the following Rules:

A
  • Large effect size: d = 0.8
  • Medium effect size: d = 0.5
  • Small effect size: d = 0.3
52
Q

It can be as low as 0 (It can not be negative) and, unlike a correlation (which can not be higher than 1), it has no upper limit, although values above ___are rare.

A

1

53
Q

Compares two unrelated groups.

  • Used when independent samples t-test can not be used.
  • Non-parametric test
A

The Mann-Whitney U Test

54
Q

The t-test compares the means of two groups and tells us whether the difference in the means is _____

A

statistically significant.

55
Q

The Mann-Whitney test does not compare means so it might be tempting to say that it compares _____Unfortunately it does not (necessarily

A

medians.

56
Q

Use the value called ___ which is the Greek Letter theta

A

ϴ
effect size for the mann-whitney test

Psych 110 (Stats) (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions