Probability and significance

• Probability- the likelihood of events being determined by chance
• Probability can never be 100% accurate because it is due to chance. A coin toss is 50/50, but you could get all heads
• Significance- a statistical term which indicates that the association between two (or more) variables is strong enough for us to accept the experimental hypothesis
• Psychologists will only accept their hypothesis if they are 95% certain
• Type 1 errors are a 'false positive'
• Type 1 errors are where the null hypothesis is rejected and the alternative hypothesis is accepted, but it should not have been
• 1% significance level is more likely to produce a type 1 error
• Type 2 errors are 'false negatives'
• Type 2 errors are where the null hypothesis is accepted and the alternative hypothesis rejected, but it should not have been
• Type 2 errors are more likely when the significance level is 1%