Progression exam - research methods Flashcards
What is a type 2 error?
Wrongly accepting the null hypothesis when it should be rejected
What is the solution to a type 2 error?
Use a bigger level of significance. E.g. instead of 0.05 use 0.1
What are the five non-parametric inferential statistic tests?
- Chi-squared
- Binominal sign test
- Mann-Whitney U
- Wilcoxon signed ranks
- Spearman rho
When would it be appropriate to use a Chi-squared test?
When testing for a difference, data is nominal and independent measures design
When would it be appropriate to use a Binominal sign test?
When testing for a difference, when data is nominal and repeated measures/ matched participants design
When would it be appropriate to use a Mann-Whitney U test?
When testing for a difference, data is ordinal and independent measures design
When would it be appropriate to use a Wilcoxon signed ranks test?
When testing for a difference, data is interval and repeated measures/ matched participants design
When would it be appropriate to use a Spearman Rho test?
When testing for a correlation, when data is interval and design is not applicable
What is the mean?
All scores added up and divided by how many scores there are
What is the mode?
The most frequent result E.g. out of 10 participants, 7 got a score of 4
What is the median?
The middle score
How would you calculate the median?
Order scores lowest to highest and identify middle score
–> If there are two add them together and divide by 2
What are the measures of dispersion?
- Range
- Variance
- Standard deviation
How do you work out the range?
Subtract lowest score from highest
How do you work out the variance
- Calculate mean for the data set
- Subtract the mean from each score in data set
- Square the result of each of these calculations
- Add all the squared results together to get the sum
- Divide the sum by the number of scores in data set
How do you work out standard deviation
Do all the steps for working out the variance but find the square root of your answer
What are the four sampling techniques?
- Opportunity sampling
- Random sampling
- Self-selected sampling
- Snowball sampling
What is opportunity sampling?
Where the researcher takes whoever is available at the time
What is random sampling?
Where members of the target population are randomly selected and all have a chance of taking part
What is self-selected sampling?
Where researchers ask people to volunteer and individuals determine their own involvement in the study
What is snowball sampling?
Where researchers rely on the participants they already have to go and find other participants
What are the strengths of opportunity sampling?
- Easy technique - sample can be acquired quickly
–> Can also be acquired inexpensively
What are the weaknesses of opportunity sampling?
- Participants may not be a representative sample
- Usually drawn from very small sample
What are the strengths of random sampling?
- Avoids researcher bias - every member of target population has equal chance of being selected
- Most representative technique
