0. Statistical Analysis

Question 1

statistical analysis

Answer 1

part of mathematics that studies the collection, organization, analysis, interpretation, and representation of data

Question 2

What to do if I want to find if the data is randomized

Answer 2

To find if data is normally distributed (randomly collected) I need to draw a distribution graph. If the graph is “bell-shaped” then the distribution is normal.

Question 3

What percentage of data should fall within one standard deviation of the mean on a distribution graph?

Answer 3

Approximately 68%.

Question 4

What percentage of data should fall within two standard deviations of the mean on a distribution graph?

Answer 4

Approximately 95%.

Question 5

What percentage of data should fall within three standard deviations of the mean on a distribution graph?

Answer 5

Approximately 99.7%.

Question 6

error bar

Answer 6

a vertical line below and above the mean value - it shows the variability of data

Question 7

Error bars can show:

Answer 7

1. The range of data
   - a line extends from the highest to the lowest value of the data set
2. STDEV
   - summarizes the spread of data around the mean value (plus minus 1 stand. deviation) - tells how widely the values are spread - the more reliable way of representing the variability of a data set than the range

Question 8

two hypotheses in a t-test

Answer 8

• null/zero hypothesis (H0)
• alternative hypothesis (H1)

Question 9

null hypothesis

Answer 9

always negative - claims that there is no significant difference between two sets, any observed difference is due to chance selection of data (claims the lack of effect of the investigated IV on the DV)

Question 10

alternative hypothesis

Answer 10

claims that there is a significant difference between the two sets (the investigated IV does affect the DV)

Question 11

“P” is the probability that…

Answer 11

…you’ll get the result you did if there is no significant difference between the 2 sets (the null hypothesis is correct)
- IV doesn’t impact the DP

Question 12

If P<0.05…

Answer 12

…the sets are different (H1 is correct).

Question 13

If P>0.05…

Answer 13

…the sets are the same (H0 is correct).

Question 14

Even if the two bell shapped frequency distribution graphs overlap this can be determined as insignificant if…

Answer 14

…the values’ means are far apart. However, the P value must be calculated to confirm that they are not part of the same set.