Research Methods: Data Flashcards
What is a correlation?
A mathematical technique in which a researcher investigates an association between two co-variables.
What is a positive correlation?
As one co-variable increases, so does the other, e.g. the number of people in a room and noise tend to have a positive correlation.
What is a negative correlation?
As one co-variable decreases, the other also decreases, e.g. the number of people in a room and personal space tend to have a negative correlation.
What is a zero correlation?
When there is no relationship between the co-variables.
What is the difference between a correlation and experiment?
- In experiments the IV is manipulated by the researcher, so a cause and effect relationship can be established.
- In a correlation no variables are manipulated by the researcher so we cannot establish a cause and effect relationship (even if there is a positive correlation, we cannot ensure that the two co-variables have a cause and effect relationship).
Give strengths of correlations:
- They are a useful tool in research through providing a precise and quantifiable measure of how two variables are related.
- Often used as a starting point before researchers commit to an experimental study.
- They are relatively quick and economical to carry out. A controlled environment and manipulation of variables are not needed. Secondary data can be collected by others, meaning that correlations can be less time consuming than experiments.
Give limitations of correlations:
- Lack of variable manipulation means that correlations can only tell us how variables are related but not why (cannot demonstrate cause and effect relationship so we do not know what variable is causing the other to change- or if a change is due to untested variables).
- Correlations can be misinterpreted as relationships may be viewed as casual when they actually are not- especially by the media.
What is quantitative data?
Data that can be counted, usually given as numbers.
What is qualitative data?
Data that is expressed in words and is non-numerical.
What is primary data?
Information that has been obtained first hand by the researcher.
What is secondary data?
Information that has already been collected by someone else.
What is meta-analysis?
The process of combining the findings from a number of studies on a particular topic.
Give strengths and limitations of using quantitative and qualitative data:
Strength:
- Qualitative data provides richer detail than quantitative- allows respondent to give their feelings, opinions etc on a given topic- greater ecological validity as it provides a more meaningful insight into respondents worldview.
- Quantitative is easier to analyse and draw comparisons from. The data is more objective and less open to bias.
Limitations:
-Qualitative is difficult to analyse and summarise statistically, so comparisons are difficult to make. Conclusions may rely on the subjective interpretations of the researcher and may be subject to bias (especially of the researcher has preconceptions about what they expect to find).
Give strengths and limitations of using primary and secondary data:
Strength:
- PD is authentic data collected from the Ps themselves for the purpose of the investigation specifically- e.g. questionnaires and interviews can be designed in a way so they specifically target what information the researcher wants.
- SD is inexpensive and easier accessed. The researcher using the SD may find that all the information they need has already been collected so they don’t need to carry out a PD collection.
Limitations:
- PD requires time and is expensive e.g. conducting an experiment requires considerable time and resources, and this is a limitation when compared to SD which takes minimal time and effort to collect.
- SD may lack quality and accuracy- e.g. investigation may first appear to be valuable and promising, but on further investigation may be outdated or incomplete.
Give strengths and limitations of using a meta-analysis:
Strength:
- Allows us to create a larger, more varied sample and results can then be generalised across much larger populations.
Limitation:
- Prone to publication bias- where the researcher may not select all relevant studies, choosing to leave out those with negative or non-significant results- so conclusions from the meta-analysis will be biased because they only represent some of the significant data.
Name the measures of central tendency:
Mean
Mode
Median
Name the measures of dispersion:
Range
Standard Deviation
What is a normal data distribution?
- A symmetrical spread of frequency data that forms a bell-shaped pattern.
- The mean, median and mode are ALL located at the highest peak.
What is a skewed data distribution?
- A spread of frequency data that is not symmetrical, where the data clusters to one end.
- Either positive or negative
What is a positive skew?
A type of frequency distribution where most of the data is towards the left.
What is a negative skew?
A type of frequency distribution where most of the data is towards the right.
What is the sign test?
A statistical test used to analyse the difference in scores between related items.
What are the 3 conditions needed to do a sign test?
- Look for difference (rather than association)
- Repeated measures design
- Nominal data
What is a directional (one-tailed) hypothesis?
States the direction of the hypothesis
