Brainscape's Knowledge GenomeTM

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


See full index

research + data > chi-squared and t-tests (w6) > Flashcards

chi-squared and t-tests (w6) Flashcards

1
Q

what test to use when proportions with more than 2 levels

A

chi-squared goodness of fit test

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

what test to use when comparing proportions across 2 or more groups

A

chi squared test of association

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

what test to use when comparing a measure with a fixed value

A

one sample t test

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

what test to use when comparing a measure across 2 groups ( independent and paired )

A

independent: two samples t test
paired: paired t test

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

what test to use when comparing measure across more than two groups

A

ANOVA

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

what is chi squared a test of

A

test of difference among categorical (nominal and ordinal) variables

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

what are two types pf chi squared test

A

goodness of fit
test of association (or test of independence)

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

what is chi squared goodness of fit test for

A

how proportions in data fit to fixed (expected) proportions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is chi squared test of association for

A

how proportions of two data sets are associated

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

what is Benford’s law, aka

A

first digit law
the frequency of first digits of naturally occurring numerical data follow a particular proportion (eg prices, populations, lengths)

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

what does the chi squared test for Benford’s law test

A

whether the frequencies of first-digits of the data follow the known proportion

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

what is null for testing Benford’s law, what does it mean if its rejected

A

Benford’s law is preserved (i.e. numbers are naturally occurring)
data set is likely fabricated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how to report chi squared goodness of fit test

A

the X2 value for df followed by p-value
eg: X2 (5) = 12.2, p=0.032

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

in chi squared goodness of fit test, what does bigger X2 mean

A

bigger difference

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

what can descriptive statistics for chi squared test of association be summarised as

A

contingency table

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

how to report chi squared test of association results

A

X2 value with df and N (number of samples) followed by p-value
eg: X2 (2, N=27) = 1.43, p = 0.490

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

what’s a paired sample

A

means data points are paired across 2 groups
eg is variables are mom L or R handed and daughter is L or R handed, mom-daughter data need to be paired

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

when can McNemar’s test be used

A

only for 2 dichotomous variables (ie 2-by-2 contingency table)

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

what is t test for, what variables

A

difference in group of measures (interval or ratio variables), compare means of populations (3 or more means use a different test)

20
Q

what is null hypothesis for t test

A

that means are equal

21
Q

what are three types of t test

A

one sample
independent (unpaired) samples
paired samples

22
Q

what you can decide for each t test

A

whether to do a one-tailed or two-tailed test

23
Q

what test for nominal/ordinal variables the one sample t test corresponds to

A

binomial or chi squared goodness of fit

24
Q

what test for nominal/ordinal variables the independent (unpaired) samples t test corresponds to

A

chi squared test of association

25
Q

what test for nominal/ordinal variables the paired samples t test corresponds to

A

McNemar’s test

26
Q

whats the one sample t test for

A

compares mean of one sample group against a fixed value

27
Q

what is independent samples t test for, why is data called independent

A

compare the observed difference between the means of two independent samples or categories
data is from different groups

28
Q

what is paired samples t test for

A

compare the main difference of one group measure on two occasions

29
Q

what does normality assumption for t test mean, what is this called

A

sampling distribution of the mean is normal
central limit theorem

30
Q

what are statistical tests based on normality assumption called

A

parametric tests

31
Q

how to check normality assumption, what indicates violation of normality

A

test of normality (shapiro-wilk test)
low p value (p<0.05)

32
Q

what’s an assumption for independent samples t test

A

equality of variance: variance of 2 populations are equal

33
Q

how to test equality of variance, what is p value in this context

A

Levene’s test of equal variance,
significance of difference in variances are reported as p value

34
Q

how to know if variance is/isn’t equal, what to do if variances aren’t equal

A

p < 0.05 : variance not equal
p > 0.05 : variance are equal
use Welch’s test

35
Q

how to write result for one sample t test

A

eg: UoB students reported higher levels of stress (M = 62, SD = 4) than found in the population of the same age group,
t(36) = 2.4, p = .034

36
Q

how to write result for independent samples t test

A

There was no significant effect of gender on the exam score, t(138) = 3.7, p =.097, despite women (M = 65, SD = 8) attaining higher scores than men (M = 61, SD = 6.8)

37
Q

how to write results for paired samples t test

A

The results from the pre-test (M = 12.1, SD =1.4) and post-test (M = 14.1, SD = 1.7) memory task indicate that energy drink have significantly improve the memory, t(19) = 3.1, p = .006

38
Q

what does t value depend on

A

df = sample size - no. groups

39
Q

what does greater t value mean

A

greater difference, usually reported with M and SD

40
Q

when to use one sample t test

A

one group, normality

41
Q

when to use Wilcoxon signed ranks test/one-sample median

A

one group, no normality

42
Q

when to use independent samples t test

A

two groups, unpaired, normality, equal variance

43
Q

when to use Welch’s test

A

two groups, unpaired, normality, no equal variance

44
Q

when to use Mann-Whitney U test

A

two groups, unpaired, no normality

45
Q

when to use paired samples t test

A

two groups, paired, normality

46
Q

when to use Wilcoxon signed ranks test

A

two groups, paired, no normality

research + data (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions