Stats - 1

Question 1

What are the definitions of mean and standard deviation? What do they mean in terms of data distribution?

Answer 1

Mean - the average value of the data

SD - The average distance of the data collected from the mean

Mean - how data is concentrated

SD - how data is separated

Question 2

What are frequency and distribution of data in statistics? What relationship exists between the 2?

Answer 2

Frequency - how many times a value occurs

Distribution - pattern of all samples plotted together

Frequency constructs the distribution

Question 3

If a huge number of samples are collected with natural characteristics, it will form a normal distribution - what is this? At the peak of this distribution, what value is expected?

Answer 3

bell curve

at the peak, the value is the mean

Question 4

in normal distribution, how much data is included in mean +1, 2 and 3 standard deviations?

Answer 4

68%
95%
99%

Question 5

What kind of files can be imported into SPSS?

Answer 5

excel

txt

Question 6

What 3 data types are there in statistics?

Answer 6

numeric
ordinal
nominal

Question 7

What data characteristics can be shown in statistics with a histogram?

Answer 7

frequency and distribution

Question 8

What can users do with the variable view interface?

Answer 8

define variables and create a data table for them

Question 9

in SPSS, what can users do with the data view interface?

Answer 9

edit data

import data

Question 10

In statistics what is the definition of the median? what is the difference between mean and median?

Answer 10

Median is the middle value. Either average of the two middle numbers or the middle number once data has been numerically ordered

mean is not a sample value, median is.

Question 11

What are the meanings of maximum and minimum in sample data?>

Answer 11

the top and bottom value collected

Question 12

What can users do with the crosstab function in SPSS?

Answer 12

Can enter two variables into a table and calculate a chi-square for them

Question 13

In the use of error bars on graphs, what do the circles and dashes represent?

Answer 13

circle - mean

dash - SD, SEM

Question 14

What chracteristics from two variables can be shown using the scatter dot graph?

Answer 14

trend and association between two variables

Question 15

What type of files can be exported from SPSS?

Answer 15

excel 
txt 
word file 
graph 
html

Question 16

If two sets of sample data have different means, are their global means significantly different? why?

Answer 16

Not sure - it could be the sampling or the research method causing the difference

Question 17

In test of hypothesis, what are primary/null hypotheses?

Answer 17

no significant difference between groups i.e. p >0.05

Question 18

What significance levels are normally used in test of the hypothesis?

Answer 18

p >0.05 signifies no significant difference between data sets

Question 19

When comparing two sets of data, under what condition are two groups of data considered to be significantly different in terms of statistics?

Answer 19

p<0.05

Question 20

What do single and double asterisks mean in terms of statistics?

Answer 20

• • p<0.05

** - p<0.01

Question 21

Under what condition is the primary hypothesis accepted?

Answer 21

p>0.05

Question 22

What main indices will influence the results of a test of hypotheses?

Answer 22

mean
sample size
standard deviation
significance level (p value)

Question 23

In which situations can a t-test be applied?

Answer 23

numeric data with normal distribution and a small sample size

Question 24

If a group of subjects are measured twice in a time interval, are the results dependent or independent?

What statistical method can be used to compare the means?

Answer 24

Dependent

paired t-test

Question 25

If subjects are treated in different ways e.g. different hip implant, are the results dependent or independent of eachother?

Answer 25

independent

Question 26

What statistical method can be used to compare the means in independent data sets?

Answer 26

independent sample t-test

Question 27

in what situation is a paired t-test used?

Answer 27

dependent data sets

Question 28

in what situation is an independent sample t-test applied?

Answer 28

independent data sets

Question 29

If the data is not continual, can a t-test be applied?

Answer 29

no