Research Methods - Data analysis, interpretation and reporting Flashcards
All AS and A2 research methods on the AQA psychology specification are covered as part of this deck
Significance level most often used in Psychology
P<0.05
Determination that the results are significantly strong to reject the null hypothesis
Significance
The likelihood that certain events will occur
Probability
The value a test statistic must reach in order to consider the result significant
Critical value
The value of a statistic that is calculated for a particular data set (outcome of the stats test)
Calculated value
(False-positive) occurs if an investigator falsely rejects a null hypothesis that is actually true in the population
Type I error
(False-negative) occurs if an investigator fails to reject a null hypothesis that is actually false in the population
Type II error
Decreasing the probability of a type I error increases…
the probability of a type II error
How to decrease the likelihood of a Type I error
Use a smaller significance level (P<0.01)
How to decrease the likelihood of a Type II error
Increase the sample size in the study
Choose the test: Difference, nominal data, Independent Measures
Chi Squared (x2)
Choose the test: Difference, at least ordinal data, independent measures
Mann Whitney U (U)
Choose the test: difference, interval/ratio data that is normally distributed, Independent measures design
Unrelated t-test (R)
Choose the test: difference, nominal data, repeated measures
Sign test (S)
Choose the test: difference, at least ordinal data, repeated measures design
Wilcoxon t test (T)
Choose the test: difference, internal/ration data that is normally distributed, repeated measures deign
Related t-test (R)
Choose the test: Correlation, nominal data
Chi Squared (x2)
Choose the test: correlation, at least ordinal data
Spearman’s Rho (Rs)
Choose the test: Correlation, interval/ratio data that is normally distributed
Pearson’s product moment
Sign test: should the calculated value be greater than or less than for significance?
Equal to or less than
Mann Whitney U: should the calculated value be greater than or less than for significance?
Equal to or less than
Wilcoxon: should the calculated value be greater than or less than for significance?
Equal to or less than
Chi Squared: should the calculated value be greater than or less than for significance?
Equal to or greater than
Unrelated t test: should the calculated value be greater than or less than for significance?
Equal to or greater than
Related t test: should the calculated value be greater than or less than for significance?
Equal to or greater than
Spearman’s Rho: should the calculated value be greater than or less than for significance?
Equal to or greater than
Pearson’s Product moment: should the calculated value be greater than or less than for significance?
Equal to or greater than
Which inferential statistic do I have to calculate by hand?
Sign test
Examples of descriptive statistics
Central tendency, measures of dispersion, charts and graphs
Measures of central tendency show what
The average of a set of data (mean, median or mode)
The mean is..
found by adding all scores and dividing by the number of scores - the arithmetic average
The median is..
The central/middle value (once all data is in order)
The mode is…
The most frequently occurring value
Strength of the mean
Most representative as it uses all the data scores
Weakness of the mean
Easily distorted by outliers
Strength of the median
Unaffected by extreme scores/outliers