Statistics

What does standard deviation represent?

• spread of data around the mean

How do you calculate the mean?

• add up all numbers and divide them by how many there are

How do you calculate the mode?

• most common value

How do you calculate the median?

• middle value

What does a thin and fat curve mean for SD?

What is the formula for SD?

What does it mean if SD bars overlap?

• differences in the means aren’t significant

What does Chi squared test for?

• testing for differences between categories

What is the formula for CS?

Use this example to work out CS

What is “the golden truth”?

• if the calculated value is more than/less than the critical value

• We reject/accept the null hypothesis

• The probability that the difference in the categories are due to random chance is less than/more than 5%

• The difference in categories is/isn’t significant

What is spearman’s rank? (Correlation coefficient)

• testing for a correlation between two variables

Use SR to work this example out

What is “the golden truth”?

• if the calculated value is more than/less than the critical value

• We reject/accept the null hypothesis

• The probability that the correlation is due to random chance is less than/more than 5%

• The difference in categories is/isn’t significant

What is a T-test?

• testing for differences between mean values

What is the formula for the T-test?

Work out this example

What is “the golden truth”?

• if the calculated value is more than/less than the critical value

• We reject/accept the null hypothesis

• The probability that the difference in the means are due to random chance is less than/more than 5%

• The difference in categories is/isn’t significant