Research Methods Flashcards
What is nominal data?
Data that can be categorised
What is interval data?
Data that can be measure on equal interval scales e.g. height because it’s continuous
What is ordinal data?
Data that can be placed into rank order e.g. in a race
Steps of spearman’s ranks
- Data is categorised into a table
- Data is then ranked the lowest given a rank of 1 and so on (each column ranked individually). If there is a tied score the rank scores are added and divided (e.g. 10= 3+4 / 2 = 3.5)
- 4.+5. Complete the difference (d) between the ranks. Rank 1 - Rank 2 and then squared (d2) then all the values are added together to give the sum Ed2(squared)
- Rs = 1 -6Ed/n(n2-1)
- Level of significance - this requires looking at the critical values of the spearman’s rank test in the critical value table for this test
What is a one- tailed test, what is a two- tailed test?
One tailed is a directional hypothesis
Two tailed is a non- directional hypothesis
What is inferential testing?
Ways to verify your data
Can use chi square, sign test, Mann Whitney u test, the unrelated t test, the related t test, Wilcoxon matched pairs, spearman’s rank or Pearson’s rho
Steps to complete the sign test
- Data is categorised into a table of results
- Positive and negative signs need to be added. If conditions A is a yes and condition B is a no a plus is added and the opposite would be added.
- Count up each positive and negative sign assigned to each participants scores.
- The smallest of the total direction scores is the overall t test result
- Level of significance - this requires looking at the critical values of the sign test in the values tables.
Steps to complete the Chi square test
- Label 1,2,3+4 on the observed and expected values
- Calculate the degrees of freedom and expected values: degrees of freedom = (no. Of rows - 1) x (no. Of columns - 1)
Expected values (e) = row total x column total / N - Fill out the rest of the table ( e, o-e, (o-e)2, (o-e)2/e )
- Add the last column together to get E (the sum)
- Look at the table of values to determine whether your information is valid or not
How do you work out the expected values in the chi square test?
Row total x column total/ n
What is the difference between a natural and a quasi experiment?
Natural- naturally occurring independent variable and a natural setting.
Quasi- naturally occurring independent variable in a lab setting (non-natural)
What is a type I error?
Allow yourself to find a correlation where there isn’t one. Usually when the researcher uses 5% level of significance.
What is a type II error?
When you reject your hypothesis because you have been too harsh on yourself e.g. you used 1% significance instead of 5% where a relationship could be seen.
What is the difference between parametric and non parametric data?
Parametric data can fit in a graph (It’s interval or ratio) whereas non- parametric data can’t fit in a graph.
If you are looking at a difference between variables, have nominal data and are using an independent group design what inferential test should you use?
Chi square
If you are looking at a relationship between variables, are using a correlation design, and have ordinal data what inferential test should you use?
Spearman’s rank
If you are looking at an association between variables and have nominal data what inferential test should you use?
Chi square
If you are looking at a difference between variables, have nominal data and use a repeated measures design what test should you use?
Sign test
If you are looking at a difference between variables, have ordinal/interval data, use an independent group design, and is non parametric what inferential test should you use?
Mann Whitney U test