methodology: meta analysis

Question 1

what is meant by a meta analysis?

Answer 1

• analysis of analyses, using results from different studies about the same issue.
• the compilation of multiple secondary sources of previous research
• to establish a new, combined conclusion
• reanalysing individual studies raw data using new formulas and statistical tests
• shows us new significance levels and trends in data
• focuses on the direction and size of effects across studies, not statistical significance.
• involves statistical analysis of the data from all the studies it combines to determine the influence of various factor to do with the behaviour in question

Question 2

if a number of studies separately find the same answer and a meta analysis is carried out, the answer becomes stronger because ….

Answer 2

the studies support one another, strengthening reliability

Question 3

how does a meta analysis adjudicate where studies find different answers?

Answer 3

• if one study finds that pre trial publicity has an effect on jury decision making but another study finds the opposite, this may be worthy of a meta analysis- inconsistent research
• can be used in cases where studies have come to different conclusions on the effectiveness of interventions, such as interventions for criminals

Question 4

what is primary data?

Answer 4

• info observed/collected directly from first hand experience
• data has been collected by researcher
• relates to aims/hypothesis of the study
• eg answers from a questionnaire

Question 5

what is secondary data?

Answer 5

• info gathered for a purpose other than the current one
• eg government statistics

Question 6

what data is used for a meta analysis?

Answer 6

• secondary
• requirements is that it should only contain studies that have sound methodology- so that the best evidence is pulled together into an overall analysis
• called the best evidence analysis

Question 7

describe some strengths of secondary research

Answer 7

• time and cost effective due to relying on existing data sources
• could be the only way of obtaining information about the past
• allows researchers to make comparisons over time and compare multiple sources
• can also use a larger sample size due to the secondary data- so can include a more diverse sample, increasing generalisability as findings are representative on a mass scale

Question 8

describe some weaknesses of secondary research

Answer 8

• data could have methodological flaws that the researcher is unaware of, reducing validity
• outdated so may not be representative of present population (temporal validity)
• objectives may not be appropriate for the study in question
• information may be incomplete which could be confusing for the researcher

Question 9

state the order of steps for carrying out a meta analysis NEED AO2 LINKS

Answer 9

• identify and define research question (hypothesis is produced)
• perform literature search- (identify all studies considered to be relevant and of sufficient quality- best evidence synthesis)
• select the studies/ systematic review
• data extraction- (summary of data or outcomes take from each study, include data such as sample size, methodology, measures used)
• analyse the data- (perform statistical analysis, in order to produce comparable estimates to make effect sizes)
• final estimates of effect and report the data- (draw conclusions and state trends found and the effect of size of such trends)

Question 10

what is publication bias?

Answer 10

positive studies being more likely to go to print

Question 11

what is search bias?

Answer 11

• search for studies producing unintentionally bias results
• incomplete set of keywords / varying strategies to search data bases
• search engine used

Question 12

what is selection bias?

Answer 12

• researchers should clearly define criteria for choosing from the list of potential studies
• ensures unbiased results

Question 13

Why are meta analyses conducted

Answer 13

When there is a huge body of psychological research or where research is inconsistent

Question 14

Generalisability

Answer 14

• uses secondary data
• means that larger samples of many studies in differing cultures, time periods and locations on ….can be used
• diverse sample makes the findings representative on a mass scale

Question 15

Reliability- strengths

Answer 15

• high reliability
• involves the study of quantitative data such as (crime stats of recidivism) when looking at treatments
• therefore, the analysis of treatments will be objective
• uses statistical analysis- only uses numbers- results are objective and without misinterpretation or researcher bias when analysing
• increasing consistency- can be replicated

Question 16

Applications of meta analysis?

Answer 16

A strength is that there are positive applications from meta analysis. This is because they are often used to look at the success rates of treatments and highlights issues with jury decision making. This means research can be used to help show the effectiveness and so can possibly lead to new treatments.

Question 17

Validity- weaknesses

Answer 17

• small studies have different designs- can become part of a confounding variable when in meta analysis- direct comparison cannot be easily made
• experimenter bias- you pick which studies are used- researcher may only pick ones that agree with the hypothesis (so selective in picking secondary data
• publication bias- only successful research is published- which may bias the meta analysis

Question 18

Ethical?

Answer 18

A strength of meta analysis is that it is highly ethical. This is because it uses pre-published secondary data which doesn’t directly involve the use of ppts. Therefore, the ethical guidelines don’t need to be considered to avoid harm to ppts or informed consent which may have cause problems in research. Additionally, it is time and cost effective as data has already been gathered, which means conclusions on… will be made at a time when they will still benefit society.