Issues in research methods Flashcards
(46 cards)
Who created the hypothetico-deductive method?
Karl Popper
What are the 8 stages of the hypothetico-deductive method?
Theory -> hypothesis -> operationalisation of concepts -> selection of participants -> survey studies/experimental designs -> data collection -> data analysis -> findings
What did Popper (1972) argue about how we know what to test?
Research begins with the identification of a particular problem/issue and further suggested that there are 2 possible sources of research ideas: casual observation and previous research
What is casual observation in the generation of research ideas?
A researcher spots a new phenomenon for the first time and decides it is worthy of investigation
How does previous research inform new reserach ideas?
Can motivate new research projects for a number of reasons e.g. replication/generalisation/original findings/testing ideas in a new context/zooming in to look at underlying processes
What do surveys measure?
Variables as they naturally occur e.g. physical activity and wellbeing in general public
- variables measured, not manipulated
- Dependent on sampling, may be generalised to wider population
What is the function of experiments?
Manipulating variables to isolate their effects to establish a causal relationship through randomisation, and holding other factors constant
What is systematic variation?
Variation that can be explained by model (statistic)
What is unsystematic variation?
Variation that cannot be explained by model (statistic)
What is the equation for a test statistic?
Variance explained by model (systematic) / variance not explained by model (unsystematic) = test statistic
Effect / error = tests statistic
What is H1?
The effect you expect to find (alternative hypothesis) - related to systematic variation
What is H0?
Null hypothesis - no evidence of effect - related to unsystematic variation
What is the process of hypothesis testing?
- pose hypotheses (one or two tailed)
- analyse data (test model - error:effect ratio)
- calculate probability of getting result if null hypothesis is true (p > .050, result is significant)
- When to reject/fail to reject null hypothesis (don’t accept alt/experimental hyp, just infer evidence of effect)
What is a type 1 error?
Incorrect rejection of null hypothesis
False positive
Conclude there is an effect when there is none
What is a type 2 error?
Incorrect rejection of alternative hypothesis
False negative
Conclude there is no effect when there is one
What are 2 limitations of relying on hypothesis testing (significance)?
- focus on whether or not result is significant statistically, but not necessarily in broader sense
- does not give indication of size of statistical effect
What does the alpha level predict?
Probability of making a type 1 error - saying there is an effect when there isnt (typical value = 0.05)
What does the beta level predict?
Probability of making a type 2 error - saying there is no effect when there is one (typical value = .20)
What do effect sizes attempt to address?
Type 1 errors - can be significant but too small to be practically meaningful
What are effect sizes also referred to?
Magnitude of statistical effect found
What do effect sizes allow us to investigate?
How big a difference / relationship has been found
To compare findings across studies to gauge real-world importance
What does the type of effect size used depend on?
The type of test used
What are the values for small, medium, and large effects for Cohen’s d?
Small = .2
Med = .5
Large = .8