16. Mathematical Content Flashcards
What is statistical testing?
Determines whether hypotheses should be accepted or rejected, whether differences are statistically significant or if they have occurred by chance
What is the sign test ?
A test used to analyse the difference in scores between related items
What are the three features we need to use the sign test ?
- look for a difference rather than association
- Use a repeated measures design
- Nominal data (organised into categories)
What is the accepted level of probability?
0.05
What does it mean if the experimental hypothesis is accepted and is less than 5% ?
The researcher can be pretty certain that the difference found was because of the manipulation to the IV
In which circumstances might the significance level be 0.01 ?
When there is a human cost e.g. drug trials or the investigation is a one off
What is the critical value used for ?
The critical value is compared to the calculated value to decide whether the results is significant or not
What three things do you need to use the table of critical values ?
- The significance level desired
- The number of participants
- Whether the hypothesis is directional (one tailed) or non directional (two tailed)
What is the first step in doing a sign test ?
- Convert to nominal data - subtract the control group from the experimental condition and record whether it is a positive or negative sign
E.g experimental - condition
What is the second step on working out the sign test ?
- Add up the pluses and minuses
What is the third step in the sign test ?
- Take the less frequent sign and call it S
What is the fourth step in the sign test ?
- Compare calculated value with critical value. If the calculated value is less than or equal to ten your hypothesis is significant
