Statistics Flashcards

1
Q

sampling bias

A

when sample isn’t representative of the population

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

3 types of correlational research

A
  1. naturalistic observation
  2. survey application
  3. documentary research
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

3 categories of descriptive statistics

A
  1. distribution
  2. central tendency (mean, median, mode)
  3. measures of variability (range, standard deviation, variance)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

inferential statistics meaning

A

drawing conclusions about population’s features based on results from test

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

one sample t-test meaning

A

comparing mean sample of population and small sample taken from population

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

two-sample t-test meaning

A

comparing mean values of independent sample 1 and independent sample 2

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

paired sample t-test meaning

A

comparing value of sample 1 at time 1 to value of sample 1 at time 2

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

when do we have strong positive correlation?

A

When Pearson’s r is bigger than 0.5

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

operational definition meaning

A

precise description of how variables will be measured

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

true experiment

A

scientist has complete control over manipulation of IV + random allocation

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

randomised control trial

A

scientific experiment where similar people allocated to 2 groups to test intervention

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

cross sectional research
benefits
disadvantages

A
  • data collected in one specific point in time to compare subgroups

benefits:
+ compare subgroups

disadvantages:
- no measures over time

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

systematic sampling definition

A

every nth person gets chosen

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

stratified sample definition

A

type of random sampling

population divided into groups based on characteristics then randomly selected from those

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

cluster sampling

A

all population divided into clusters

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

4 non-probability sampling methods

A
  1. non-convenience sampling
  2. purposive sampling
  3. quota sampling
  4. snowball sampling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

purposive sampling definition

A

handpicked participants based on their characteristics

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

nominal data definition

A

data without numerical value

*colours of rainbow
*countries

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

ordinal data definition

A

categories with specific order that can be ranked

*military ranks
*economy classes

20
Q

continuous variables

A

numerical that can assume any number

*weight
*temperature

21
Q

interval variables definiition

A

ordered + quantifiable but with no true zero

  • temperature in the sense that 0 celsius isn’t absence of temperature
22
Q

ration intervals

A
  • quantitative but have an actual zero

*height
*income

23
Q

normal distribution characteristics

A
  1. mean = 0
  2. SD = 1
  3. kurtosis = 3
  4. tails touch x axis at infinity (never)
24
Q

one tailed directional hypothesis

A

predicts direction of effect

reading will equal HIGHER intelligence levels

25
two tailed directional hypothesis
predicts that IV will impact DV but doesn't say what direction reading will have direct impact on intelligence levels
26
type 1 error
false positives - reject null when null is actually true
27
type 2 error
false negative - accept null hypothesis when alternative actually true
28
2 tests for between groups
- independent samples t-test (parametric) - mann-whitney U test (non-parametric)
29
parametric meaning
evenly distributed
30
non-parametiric
not evenly distributed
31
2 tests within groups design
1. related samples t-test (parametric) 2. Wilcoxon signed rank test (non-parametric)
32
what does correlation analysis tell us
1. direction 2. strength
33
Pearson's r
- continuous variables - perfect correlation at 1 (means data points on straight line)
34
Spearmann rank order correlation (rho)
- ordinal value *ranking students' performance
35
ANOVA
- comparison of more than 2 groups
36
correlation what does it show
- degree of association between 2 variables
37
multiple regression definition
- relationship between multiple IVs on one DV IV -> predictor variable (continuous or categorical) DV -> outcome variable (continuous)
38
hypothesis definition
testable prediction of relationship between two or more variables
39
standard deviation
spread of data that shows how scores deviate from the mean square root of variance
40
variance definition
how scores are distributed around the mean
41
how to reduce type 1 error
- set lower p value
42
to reduce type 2 error
- pick bigger sample size - increase p-value (increases chance of type 1 error)
43
when to use mann Whitney
for independent samples t-test with non parametric data
44
when to use Wilcoxon
paired samples t-test with non-parametric data
45
does correlation have independent variable?
- NO! we don't manipulate any variables just look at the relationship
46
mode what data can it be used for
nominal data - mode is most common answer