Inferential/ Descriptive Statistics

Question 1

What is a Skewed Distribution Curve ?

Answer 1

• Skewed distribution curves are not symmetrical at the mean (or median or mode) point.
• A skew can be positive or negative.

Question 2

Describe a Positive Skew

Answer 2

• The curve point ends or “tail” will be longer where a majority of scores are larger.
• The measures of central tendency (mean, median and mode) will decrease in value.

Question 3

Describe a Negative Skew

Answer 3

• The curve point ends or “tail” will be longer where scores are the smallest.
• The measures of central tendency (mean, median and mode) will increase in value.

Question 4

How do Inferential Statistics help us ?

Answer 4

• Help us make inferences about our data to draw meaningful conclusions.
• Different tests are used in different situations.
• This is also the reason we use two hypotheses – the alternate and the null.

Question 5

What is the aim of Statistical Testing ?

Answer 5

• Aim to reject the null hypothesis.
• We can do this if we can show it is unlikely that our results occurred by chance.
• This depends on probability.

Question 6

When can you say that test results are significant?

Answer 6

-If a test shows that it is likely results did not occur by chance

Question 7

What is the Observed Value?

Answer 7

• Each test calculates a single number – the observed value from the scores found in the study.
• This is then compared with the critical value on a table – which tells us whether it is significant or not significant.
• The key to this is the significance level – otherwise known as the probability.