Inferential stats

Question 1

What is nominal data?

Answer 1

-Represented in the form of categories
-The most basic type of data
-Can count number in each category eg. number of boys and girls in year group
-Variables are non-numeric

Eg. What is your favourite breakfast?

Question 2

What is ordinal data?

Answer 2

-Data is ordered in some way
-The data does not have equal measures
-Subjective
-Scores can be ranked in order but the gaps between the scores aren’t equal

Eg. scores on a stress test

Question 3

What is interval data?

Answer 3

-Data is based on numerical scales which are meaningful and have equal units
-Most precise form of data
-Objective

Eg. Time, temperature, weight

Question 4

What is meant by inferential statistics?

Answer 4

How do we know if the data gathered from our study is true or did we find it by chance?

Question 5

What does P<0.05 mean in words?

Answer 5

The probability of the results being due to chance is less than 5%

Question 6

If it is P<0.05, do we accept or reject the hypothesis?

Answer 6

Accept as it is likely not due to chance

Question 7

What does P>0.05 mean in words?

Answer 7

The probability of the results being due to chance is greater than 5%

Question 8

If it is P>0.05, do we accept or reject the hypothesis?

Answer 8

Reject as it is most likely due to chance

Question 9

Why do psychologists use the 0.05% level of significance?

Answer 9

If they accept the hypothesis, they are 95% sure the results are not due to chance

Question 10

What is a type 1 error?

Answer 10

When we accept the alternative/experimental hypothesis when in fact the results were due to chance

Question 11

What is a type 2 error?

Answer 11

When we reject the alternative/experimental hypothesis due to the independent variable

Question 12

What are the 3 conditions for choosing a statistical test?

Answer 12

1. Difference or correlation
2. Design of the study (independent groups, repeated measures, matched pairs)
3. Level of measurement

Question 13

Revise the table!

Answer 13

.

Question 14

What is the calculated value?

Answer 14

Each test involves taking the data collected in the study and doing a set of calculations as directed in the test instructions. Eventually a single statistic will be arrived at

Question 15

What is the critical value?

Answer 15

To decide if the calculated value is significant, the value has to be compared to another number that is found in a table of critical values

1. Value of N is the number of participants
2. Level of significance (usually 0.05)
3. One or two tailed test (directional or non-directional hypothesis)