Statistical Tests

What are inferential statistics?

Statistical tests that researchers can infer the likelihood that their data is accurate

What is a correlation? (2)

examining the relationship between two or more variables without manipulating them, cannot determine causation

What is an experiment? (2)

manipulating one or more independent variables to observe their effect on a dependent variable, controls other factors allowing researcher to determine causation

What is a Type I error?

a false positive, as a result of being too lenient

When does a Type I error occur? (4)

when the researcher has made the level of significance too high, giving themselves too large a margin for error, leads to incorrectly accepting alternative hypothesis, when p=0.1

What is a Type II error? (2)

false negative, when researcher is too stringent

When does a Type II error occur? (4)

when the researcher has made the level of significance too low, leaving too little a margin for error, leads to incorrectly accepting the null hypothesis, when p=0.01

When is a level of significance of p=0.01 used? (2)

in socially sensitive research, to be as sure as possible that findings are correct

Why is a level of significance of 0.05 used generally in Psychology? (2)

p=0.05 minimises the chances of both type I and type II errors, as it equally balances the risk of both errors

What is nominal data?

Data that is categorised by frequency of participants

What is ordinal data? (3)

Numerical data that is not in a standardised format, as it is determined by the researcher, the intervals are not equal

What is interval data? (3)

Numerical data that is in a standardised format, there are equal intervals, e.g. temperature

What are 3 pieces of information required to determine which statistical test should be used?

type of data whether it is nominal, ordinal or interval, if it is a test of difference or a correlation, if it is related data or unrelated data/what experimental design is being used

What is the mnemonic for remembering the order of statistical tests in the table? (8) (C counts for 2 columns)

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