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Flashcards in Mock Questions Deck (52)
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1

What does the mean describe?

How data is concentrated

2

What does standard deviation describe?

How data is separated

3

How is the mean calculated?

Sum of all the samples / no. of samples

4

How is SD calculated?

Square root of:
Sum of (x - mean) squared / n-1

5

What shape is ND graph?

Bell curve

6

Where is the mean on a ND graph?

Peak

7

How much data is included in the ranges of mean +/- 1, 2 and 3 SD's?

+/- 1 SD = 68%
+/- 2 SD = 95%
+/- 3 SD = 99%

8

What forms can be inputted to SPSS?

txt
excel
input manually

9

What are the 3 types of data?

Numerical
Nominal
Ordinal

10

What is nominal data? Give an example

Categories without rank
(e.g. gender, colour weekday, place)

11

What is ordinal data?

Categories with rank
(e.g. pain, satisfaction, comfort)

12

What data characteristics can be shown using a histogram?

Frequency and distribution

13

In SPSS, what can users do on variable view?

Define variable

14

In SPSS, what can users do with data view?

Input and edit data

15

What is the median?

Middle number when the data is ordered

16

What does the crosstab function do?

Arranges 2 variables into a table
Can calculate hypothesis and chi square directly

17

What is an error bar?

Mean with: SD, SEM or 95% CI

18

When should an error bar be used compared to a box plot?

Error bar - when data is ND
Box plot - when data is not ND

19

What is a box plot?

The median (50%)
Quartiles (25% and 75%)
Extreme values (min and max)

20

What does a scatter/dot graph show?

Data trends/patterns between 2 variables

21

How is SEM calculated?

SD / square root of n

22

What does 95% CI mean?

Confidence that the range will include 95% of local mean

23

When is the median more useful than the mean?

When the data is not normal distribution

24

How is variance calculated?

The square of SD

25

What is a pie/bar chart useful for showing?

Proportions and percentages in data

26

In SPSS how what can data be exported as?

txt
excel
Word file
HTML

27

If p is LESS THAN 0.05 what does this mean?

SIGNIFICANT DIFFERENCE

28

If p is GREATER THAN 0.05 what does this mean?

NO SIGNIFICANT DIFFERENCE

29

What do * and ** mean?

* p <0.05
** p 1,0.01
SIGNIFICANT DIFFERENCE

30

When would you accept the null hypothesis?

If p < 0.05

31

What are the key indices used in test of hypothesis?

Mean
SD
Sample size
Significant level (p)

32

What is the difference between dependent and independent data?

Independent - measurements done once for each individual
Dependent - samples taken two/multiple times for each individual

33

What are the 3 indications to use an independent t test?

Normal distribution
Numerical data
Small sample size (big still ok)

34

What test should be used for dependent data?

Paired t test

35

What is an alternative if data is not suitable for t test?

ANOVA

36

What result from ANOVA would indicate the need for a post-hoc test?

p < 0.05 to check which pair ARE SIGNIFICANTLY DIFFERENT

37

What assumption is made when using a Chi square?

All groups have the same chance (equal no. from each group)

38

What test methods can be used for data that is not numerical or normal distribution?

Wilcoxon signed-ranked test
Mann-Whitney U test

39

When is a Wilcoxon signed-ranked test used?

For non-numerical or normal distribution data that is related/paired/dependent

40

When is Mann-Whitney U test used?

No requirements on data distribution
Usually ordinal data
Also scale if the data is not normal distribution

41

What is the correlation coefficient used to quantify?

How variables are linearly correlated

42

What results would be expected for correlation and what do they mean?

Value between -1 and 1
0 is the worst value for correlation
Closer the value to 1 or -1 the more correlated

43

When should linear regression be used?

If 2 variables have a significant linear correlation

44

What is the purpose of linear regression?

To construct an equation to describe the relationship between the 2 variables

45

What form does a linear regression equation follow?

y - b1 + b2x
(y = mx + c)

46

What does b1 mean in a linear regression equation?

The intercept

47

What does b2 indicate in a linear regression equation?

The gradient of the slope

48

What is the purpose of survival analysis?

To analyse how a ratio of occured to inon-occured cases changes with time

49

What is needed for survival analysis to work?

Large sample size

50

What is the purpose of meta analysis?

To compare different opinions by analysing multi source data to find which is the favourite by most studies

51

What is needed for meta analysis to work?

Data needs to be in similar format

52

What does Ho state?

There is no significant difference between 2 groups