Understanding research, unit 2

What is central tendency

• A value that is representative of the entire dataset, summarising the data

• eg mode, median and mean

What is variability in data

Gives us an insight into the spread of data around those central tendencies

What is standard deviation

• Tells us how far, on average, each score lies from the mean

• Large numbers= greater variability, less consistency

• Small numbers, less variability, more consistency (so smaller SD are better)

What is standard error of mean

• An estimate of dispersion,

• The larger the sample size, the more likely the data is representative of the population, therefore less variability and smaller SE

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Sample vs population

• A population is every possible member of a defined group

• Can be broad or specific

• As psychologists, it is difficult to test entire populations, so we sample people from identified populations

• Sample procedures can influence how representative a sample is of the population, and how we can generalise findings

What is generalisation

• Whatever we find out about the sample, we assume is an estimate of what we would find if we test the entire population

• Mean, SD are estimates of what we woulde find in a population

• Therefore large samples are important as we generalise findings from sample to the population

What is data visualisation

• Analysing the relationships, patterns, trends and distributions within the data to gain insights and interpretations

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What are bar graphs most suitable for + limitations

• Comparing quantities, eg average scores of different groups

• However a limitation is that they oversimplify data, can lose nuances eg how much variation exists within each group

When are line graphs most suitable for +limitations

• When categories on the X axisare numerical and may have an order

• Used to illustrate trends

• Limitations include implying continous change where there might not be one, if there are too many data points/lines, then they can become cluttered and hard to read